X2 - Have always stored my previous TTs with jacks down all winter, and now the 5er already has the landing gear down, so the rear jacks are down as well. Never had a mouse problem, or any other problem, for that matter. As for the small amount of water - should be no problem as you describe it.
2003 Ford F-350 V-10 Crew Cab 4WD Long Bed
2004 Jayco Designer Medallion 29 RLTS 5th wheel
Bill, Gayle, and Mindi (dachshund)
Retired at last !
Nothing is foolproof to a sufficiently talented fool.