CRJ-700 Captain reported the failure of the #2 IDG and lack of transfer caused multiple systems failures during approach. The flight continued to destination and landed safely.

Narrative

We were approximately 20 minutes from ZZZ when we received numerous status messages and a Hydraulic System 3 low pressure message. My FO (First Officer) retained the flight controls and took over the radios while I checked the QRC. Before proceeding to the QRH we scrolled through the electrical synoptic pages and discovered we had magenta GEN2; IDG2; AC BUS2; and lost TRU 2 and ESS TRU2 but had no warning or caution messages as to what the root failure was; only the associated status messages. We ran the QRH for Hydraulic System 3 and were able to regain pressure by turning on Pump 3B. Next; we discussed our thoughts about the electrical malfunction and came to the conclusion that the loss of GEN2/IDG2 was the root cause of the other malfunctions. I flipped through the QRH sections relating to GEN failures. However; we were both reluctant to reset the generator or start the APU without being specifically directed to do so by a warning/caution message that directed us to the correct QRH procedure. At this point I checked in with the flight attendants. Next; I tried to text Dispatch but we had also lost all ACARS functions on the FMS. We were able to contact them through ARINC. After that I called ZZZ Maintenance and asked if they thought it would be ok to start the APU to get another generator on line. They said they didn't see a problem with that.At this point we were approaching 10;000 ft. and after another short talk we both decided we didn't want to risk making the problem worse since we weren't 100% certain what the problem was and were also only about 10 minutes from being on the ground. We coordinated with ATC to leave some space behind us since we had both flaps and slats half-speed status messages and didn't want to be forced into doing 170 - 180 kt. to the FAF. They accommodated us and once safely on the ground we started the APU; which opened the bus ties that had closed and gave us back TRU2 and ESS TRU2. GEN1/IDG1 and AC BUS 2 remained magenta.I feel we handled the situation fairly well. My FO did a great job handling the aircraft and radios and allowed me to coordinate with the company / ATC. We did go back and forth for a while about the pros and cons of starting the APU but eventually decided the safest most conservative decision was to focus our efforts on landing the plane and not introduce the possibility of further electrical problems. Had we been further from ZZZ I think we would have started the APU to avoid prolonged flight on one generator.Maintenance determined it was a GCU (Generator Control Unit) failure. They were eventually able to reset it by shutting the plane down; unplugging / plugging back in the GCU; starting the engine; and then resetting GEN2. Maintenance also said there was no history of GCU failures and that they were confident it wouldn't happen again. We flew 2 more legs with no issue.