I got to disagree with not getting the tires off the ground, depends on the ground. If/when the tires sink into the water soaked dirt, it can cause problems.
I have solid, tilt down steps. When I parked the camper in the side yard with the steps down, the tires sunk into the ground and jammed the door. I had to jack up the trailer using the stabilizers (not a good thing) to get the door open, retract the steps, and move the trailer wheels onto large boards. I had the open plastic leveler blocks under the wheels and had to pry them out of the dirt.
Now I have the TT parked in a new location beside the garage with the wheels on seperate 1&1/2" thick 20" square reinforced concrete pads (one side has two stacked for leveling. This is for all storage, not just winter. I use concrete blocks under the stabilizers for winter vice wood blocks to get buried in the snow.
If the current parking spot wasn't so unlevel, I'd consider a full concrete pad. If I leveled it, it would be a PITA to mow around.