Forgot to mention, winter is the best time to get maintenance on your boat and trailer done. I had to replace the leaf springs on my old trailer once a season this was the time. Also redid the bearing grease, took off bolts and nuts and put a little lube on them as they will become a pain if left for years. Check and replace lights/ wiring as well.

Put a cover on the boat and don't allow water or snow to build into a single spot on the cover, I have seen guys that used a 2X4 in the center of their boat to keep things from puddling but it puddled anyway. When you get a few hundreds pounds of packed snow on the canopy they had a dent and cracks through their deck where the 2x4 applied the weight.