Jesperhus in Denmark also held Virginia opossums until very recently (probably last year) in their tropical zoo. I don't actually know where they went. They built a new night zoo in 2011, actually with a rather nice collection, at least by Danish standards (rat kangaroos, tenrecs, acacia rats, Moholi bushbabies etc.), and they got hold of a couple of opossums, one of them being cross-eyed. They tried to make it a mascot like it was done with Heidi, but I don't think it ever really worked.
Then, they very suddenly started a new project - Martin & Ketils Junglezoo - which was essentially a project to advertise two popular Danish children television hosts, and the purpose with this project was that the three greenhouses should be merged to one huge greenhouse, and that all animals should be free-ranging.
Thus, they tore down the night zoo only about one and a half year after they originally constructed it, and almost all the species in there left the collection, except for the rat kangaroos and a couple of reptiles which were added to the free-ranging roster. I have somewhat mixed feelings towards this project, but well, I don't want to go off-topic by discussing it further in this thread.
In short: The opossums left the collection after a very short time and I have no idea where they went. If they went somewhere. I don't know if anyone in here can enlighten me/us as it is a rather local and not especially well-known zoo/theme park.