First, congratulations on he new TT and welcome!
I left the jacks up last winter for the same reasons stroza99 mentioned. Thoug unlikely, frost heaving is another possibility, and I didn't want to take the chance of the frame warping.
Rob & Kelly, Bella & Brady (Miniature Schnauzers)
2016 Eagle 323LKTS
2016 Ram 2500 6.7L CTD
2015 White Hawk 29REKS Summit Edition (Traded)