B-777 First Officer reported a pneumatic system warning during cruise on an ETOPS flight; entering oceanic airspace. The flight diverted to an alternate airport and landed.

Narrative

During preflight in ZZZ I noticed two status messages ECS CARD L status message and RECIRC FAN status message. Both status messages were entered into log book separately. MEL 2100B was issued for ECS CARD L which allowed display of RECIRC FAN status message and CARGO HEAT AFT advisory message (amber). We noticed the CARGO HEAT AFT (amber) message after push back and verified this matched with MEL 2100B terms with local maintenance via radio. During cruise and after just passing Location A we noticed a status message relating to PACK or the environmental control system; possibly the PACK FCV UPR R status message. After approximately 5 minutes we got BLEED LEAK R caution message. We ran the associated abnormal checklist which did not require any action from flight crew. Immediately after; that message was replaced with BLEED LOSS WING R caution message and associated abnormal checklist was completed and complied with turning off the wing anti-ice selector to OFF. We reviewed the AIR synoptic page and noted the right system being completely off including the right PACK showing off. Also; on the overhead panel the R PACK switch OFF light wast lit. I continued as pilot flying and the Captain contacted dispatch and Maintenance Control to discussed the situation on SAT com. Multiple other status messages were displayed during the remainder of the flight including TRIM AIR R. I requested Captain to check with Maintenance to see if I have to descend lower than the current altitude of FL360. Searching in Flight Manual (FM); no information was found for a limitation or a suggestion for a safe altitude with single pack. The Dispatch nor Maintenance Control were able to find a suitable altitude for continuing to ZZZ1. Captain made a decision to divert to ZZZ and informed the Dispatch. Captain also informed me that he has made a decision to return and requested me to coordinate the diversion with ATC and request priority handling. Approaching waypoint ZZZZZ I contacted ZZZ Center; requested priority handling and requested diversion to ZZZ due to right pack/pressurization related system malfunction. Dispatch informed us that we will be over weight for landing and the Captain made a decision that we will jettison fuel. As we were heading to ZZZ and descending we received clearance from ZZZ Center to begin fuel dumping.During the descend when thrust levers were at idle; ENG IDLE DISAGREE message showed in two separate occasions. A normal approach and landing was conducted and we proceeded to taxi to the gate. A few moments prior to parking break set we got the PACK R EICAS advisory; overheat at right pack outlet. ZZZ local Maintenance boarded the flight to take over the plane. A ZZZ airport operations employee who followed us from the runway to the gate boarded the plane and took down the information regarding the reason for the priority handling and my name.