Air Carrier Captain reported a Master Caution 'LANDING GEAR INOP' message at cruise. The Flight Crew continued the flight to destination airport and landed safely.

Narrative

This flight took place from ZZZ1 to ZZZ on a clear day for most of our route. Just after leveling off at cruise; the Master Caution - LANDING GEAR INOP turned on. The FO was flying and called for the checklist. We ran the checklist which led to the determination that the normal way to put the gear down (gear handle) could potentially lead to one of the gears being stuck in the nacelle. It also told us we needed to eventually run the ALTERNATE GEAR EXTENSION checklist which we knew would take about 10-15 minutes in our estimation. Funny enough; the First Officer and check pilot (who was conducting a line check) had flown together this year and had a similar issue which required them to run the ALTERNATE GEAR EXTENSION checklist. This was actually a great help to me and our decision-making process since we had knowledge from two experienced pilots who had done this procedure before in the actual airplane. With a strong headwind we knew we had plenty of time to talk and plan. We first talked to dispatch and maintenance to let them know of the situation and that we would continue on to ZZZ. They had nothing to add in terms of further instruction. After; we decided to [request priority handling] to get priority into ZZZ and to give ATC time to coordinate for us since we knew we needed to descend earlier than usual and slow down to run the checklist. Next; we made sure to keep the Flight Attendants in the loop and decided to let the passengers know later of the situation just prior to descent so they wouldn't be worrying for this lengthy leg. We tried to knock out a couple of things before descent to minimize workload while running the ALTERNATE GEAR EXTENSION checklist.The First Officer suggested I fly the plane since most of the doors and handles we had to pull were on his side; so I took the plane. We briefed threats and the plan; obtained weather and performance; as well as ran the 'Descent Checklist.' One key piece of information from the First Officer's previous time running the checklist was that if undesired indication appeared for the gear; this would extend the checklist and further lead us to another checklist which would add even more time. So the descent plan for us was a crucial part. We planned the descent very conservatively to give us ample time for any hiccups. We decided we needed to descend around ZZZ2. We further coordinated with ATC and told them our plan to start our descent to 15;000 ft. and slow to 185 KIAS near ZZZ2. We also requested XXR with a planned exit at taxiway 1. Per the checklist and the check airman's suggestion; we thought this would allow for easier taxiing since we would lose nose wheel steering once we ran the ALTERNATE GEAR EXTENSION checklist. We also called dispatch once more to update them that we requested priority handling and to request parking spots X; Y; Z; and A for straight shot off of taxiway 1. When the First Officer checked in with station; we learned they gave us A. At ZZZ2; we started our descent. Once at altitude and airspeed; we ran the checklist successfully getting the gear down. This took far less time than we anticipated; but in retrospect we would have done it the same way to give us more cushion. Once the gear was down; we advised ATC we were ready for the approach and to have a tug on standby. ATC at this point had begun vectoring us on to the ILS XXR approach. The approach and landing was non-eventful for the most part. The glide slope was dipping and rising a little more than usually most likely due to aircraft taking off; but nothing extreme. I did elect to eventually take the plane off autopilot at some point on the approach to be more stable. We landed and I did a very slow taxi off 1. I had never made any turns without the tiller; but decided I would take the taxi very slow and if I had any doubt would stop the plane and ask for a tow. Getting off taxiway 1 was no problem; lining up with the J-Line during parking was a little more difficult; but definitely safe; and doable. We parked the plane and put the discrepancy in the maintenance logbook. The First Officer and the check airmen were a great help to the success of this flight and I cannot thank them enough. Although this flight seemed very uneventful from an outside perspective; there were a lot of things in play. I had been a Captain just over X months; the First Officer had been here under a year; we were getting line checked; yet we were all able to work together as a crew and get the job done. Kudos to them and our training department. I think overall we worked well as a crew. My First Officer and check airmen were a great help. I feel as though I might have over-relied on them; but we had many good discussions in the cockpit and used everyone's perspective and knowledge to come to a safe plan. The aircraft was in control the entire time. The taxiing for me was the most unusual part. It was safe at all times; but just felt unnatural and awkward. In the end; we got the job done and didn't exceed any limitations. I definitely learned the importance of CRM. Discussing and being on the same page with one another was a key part of this flight's success. My two regrets are not giving a thorough PA to the Passengers and not checking in with the Flight Attendants fully. Although I advised the Flight Attendants that the gear was coming down early; I didn't advise the Passengers about this. I did advise them of the situation; but I hope the gear coming down earlier than usual didn't alarm anybody too much. Secondly; I believe the Flight Attendants had one more leg home to ZZZ3 after this. I'm not sure if they were working the flight or not; but I wish that we had time to debrief or talk. Although it might have been a non-event for them; next time I wish there was a way for me to stop them and make sure they were fully okay before heading off. We were already delayed as it was so they were rushed off to the next plane. I hope I have the discernment to stop the operation next time to make sure the entire crew is okay.