I have not read the whole thread, so apologies if this has been discussed, but wasn't there mention at some point of JP taking the kids sledding? Perhaps he put her body on a sled for transport...(wow, that's hard to type). In fact, I do think a lot of winter campers use sleds to transport their gear. I know I have been around ice fisherman and they drag their gear out on what I can only describe as a sled (there is probably some official name for it in the ice fishing/winter camping world).
Interesting. Yeah, they went sledding earlier in the day. But sleds are still made of wood, aren't they -- except for the runners and front. Maybe the burned wood in the hole was sled wood.