Tires aren't totally "waterproof". Given enough time you can have some infiltration of water into the tire body and from there the damage starts.
I left a trailer parked for a couple years where rainwater constantly soaked the ground where the tires sat. When I finally moved the trailer the portion of the tires that had been encased in mud had rotted. Moved the trailer about 5 miles (with fingers crossed) and when in new home I removed wheels and had new tires installed.
Ice can bring it's own problems and as to how much worse it is will depend on tire quality etc. Really a crap-shoot.
In the future I'd consider storing the trailer with it's wheels up on a couple of concrete paver's and use covers to keep snow from building up directly on the tires and supports. Either that or put the axles up on jack stands, remove wheels/tires and store inside. Cover drums/hubs with garbage bags taped in place with duct tape. Extra work in the Spring but tires will not be subject to the environment like now.
Considering the weight of your trailer a set of jack stands (4) are available for less than $100. Get them high enough and you can even let the suspension "hang" if you want and take weight off the springs/torsion tubes.
"A wise man can change his mind. A fool never will."
"You only grow old when you run out of new things to do"
2018 Flagstaff Micro Lite 25BDS
2004 Nissan Titan