Another approach is the mini hoop house. Make a rectangular frame of 2x4s on the ground long enough and wide enough to clear the ends of the boat. Drill 5/8" holes every 2' on both sides along the length of the frame. Stick one end of a 10' long 5/8" diameter piece of pvc pipe in a hole on one side, bend it over and insert the other end into the corresponding hole on the other side. Repeat until you have a neat row of u-shaped hoops. Cover, secure cover with rocks, cinder blocks etc. Chill until spring.

I have used this rig with clear plastic covering, which works well for winter gluing. It's warm in the sun, and holds the heat from heat lamps at night if it's not too cold or windy. For storage, canvas would breathe better and there would be less drip from condensation, but it is heavier and probably wouldn't shed snow as easily as plastic. I suppose you could make a ridgepole and end braces with pvc connectors and shorter lengths of pipe to stabilize the hoops.