Not sure just how much space you need, but a couple of years ago I made a small sled out of a pair of snow skis. I attached blocks from a 2 x 4 to the skies and then built a frame out of 1 x 4's that fastened to the top of the blocks. Loaded it up and started towing it out to my "spot". The skis sunk into the snow and made it impossible to pull. I gave up and pitched the ski's. I have to admit not only did I not allow enough space between the ski's and the tent, but i overloaded the setup with to much gear, 20 pound propane tank, heater, hose, enough tackle to open a store, etc. If you click above on "Search " and type in "Fish Trap Tips", you will find a ton of information, including pictures of how different sled/ski's have been set up.
As for me, I have a bid on a pair of ski's and will be making my sled all over, this time using PVC, and it will set up at least a foot off the ground, maybe higher. Hope this helps!
TrikerJohn