B767 First Officer reported receiving multiple EICAS messages on descent. Crew continued to landing.

Narrative

Flight ABCD was in a cleared descent from FL340 to cross ZZZZZ at FL280. After initializing the descent in VNAV; with thrust levers at idle; we received the following CAUTION and STATUS messages:R PACK OFF - CAUTIONL PACK OFF - CAUTIONR PACK TEMP - CAUTIONL BLEED PRSOV - STATUSR PACK - STATUSL BLEED HPSOV - STATUSR COND TEMP CONT - STATUSCaptain (PNF) asked FO (First Officer) (Relief Pilot) to pull up the FM (Flight Manual) and find the appropriate checklist; while he and FO (PF) initialed a continued descent to 9000 ft. It was observed that the cabin pressure was slowly rising due to the PACKS being disabled; so a rapid descent was initialed and cleared with ATC. Priority handling was requested; to be on the safe side. The FAs (flight attendants) were commanded to be seated immediately due to the rapid nature of the descent. Upon further observation; it was found that the L DUCT pressure gauge read '0' psi while the R DUCT pressure read just over '20' psi; with the engines supplying bleed air pressure to both systems. FO Relief Pilot initiated the L & R PACK OFF NON-NORMALS checklist while the Captain and FO coordinated the descent as required in that checklist. After completing APU start; and BLEED TRANSFER; as required in the checklist; it was initially observed that L DUCT pressure as still near '0' psi; and R DUCT pressure was in the '20' psi range. After the checklist mandated a transfer from AUTO mode to MAN mode; it was observed that the L DUCT pressure had returned to a normal '20' psi. We elected to deviate from the checklist to attempt to restore pressurization to the aircraft. We elected to return the aircraft to AUTO mode; verified continued L and R DUCT nominal pressure; and successfully reset both PACKS to ON. Left and Right PACK operation resumed and pressurization was restored to the aircraft. We concluded that it was not necessary to continue the checklist into a procedure to land unpressurized; unless the PACKS stopped functioning again. During the descent to 9000 ft; cabin pressure altitude climbed from 6000 ft to just above 8500 ft. No CABIN ALT message was observed; nor were oxygen masks deployed. No adverse conditions were experienced by cabin crew or reported by passengers. The Purser was briefed on the situation; and what to expect for the remainder of the flight; and in return the Purser briefed the cabin crew. FO Relief Pilot made a PA to the passengers; at the request of Captain; to explain the situation and what to expect for the rest of the flight and upon landing.It is noted; once pressurization was restored using APU bleed air; the following messages were present:L BLEED OFF - STATUSL BLEED PRSOV - STATUSL BLEED HPSOV - STATUSLanding was successful; smooth; and uneventful. We were met by Fire/Rescue upon exit off the runway. It was found that we could not stow the R THRST REV after slowdown from 80kts; nor after exit from the runway. Captain attempted to actuate and stow the Right Reverser several times; then decided to shut down the R ENG after sufficient time for engine cooldown and continue the taxing single-engine to our gate. Taxi to our gate was uneventful and successful. Pictures of all messages received and indications presented at failure; and after pressurization recovery we are taken; and shared with Maintenance personnel upon landing for proper documentation and diagnosis.