This is just me....I don't have any scientific or technical knowledge to back up what I'm going to say. I would not feed my family meat that has been sitting in the fridge for more than a couple of days...much less a week. So I would probably go ahead and throw the mice out as well. As well as anything else in the freezer that could spoil.

If it were just a day or so, I'd say it would be ok to refreeze them (with the increased risk of exploding meeces in the future)....but after a week or more....I'd toss 'em.

Sorry.