I'm having difficulty visualizing your set up (pics would help!) - but maybe there is a way you can provide a raised platform that is above water levels? It's just hard to know without pics. Try to get some on here and I know folks will do all they can to be of assistance.
Meanwhile, the...
Yes, they should generally live longer that that. As the post above says, they need dry conditions immediately. They need to always be indoors at night with protection from the weather (and predators) - not sure why a night pen would be saturated - doesn't it have roof and walls? During the day...