Not to worry either way. Just put it away clean and dry.

I have owned my JD LT-155 for many years. Each fall I think that it sounds like a good idea to lower the deck. Each spring I find that I have either forgot to lower it, or pushed the tractor around the shed and raised it to make it easier, then being in a rush forgotten to lower it.

FWIW I usually remove the deck for a good cleaning and spray paint the underside (rattlecan), sharpen and balance the blades, etc. etc. then Just stand the deck up along one of the walls of the barn and push the tractor "wherever." Takes up less storage space.

That's also a good time to change oil, plugs, give tractor a good cleaning, check rear end fluid.