There are no legal campsites in the pass. Just before the climb into the pass (from the Loj side), there are some designated sites and a lean-to. THis is known as Avalanche Camp. From there up to the pass is too steep to find a campsite, unless you are sleeping in a hammock. Years ago, there used to be a designated campsite just after Avalanche Lake. I don't know if it still exists... I don't know if it was legal either.. It was rather close to teh trail.
Pulling a sled.... With skis? It won't be easy. The trail is steep, zig-zaggy, and narros in places. It will be easy pulling it to Avalanche Camp and across Avalanche Lake.