There is no problem what so ever dragging a sled with a trail machine. Agreed, it's boring because you can't play as much as when you don't pull anything, but you need only one sled and you can rotate on the job.

You need only one (small) sled to bring complete, comfortable camping gear for the whole group (tent, groundsheet, sleeping pads, sleeping bags, stove). Add two jerry cans of gas, that'll more than make up for the lost mileage. Two jerry cans is about 40 kilos. Camping equipment is perhaps 40 kilos if you're generous. 80 kilos (about 160 pounds) is virtually nothing when mounted on a sled. You can easily pull that kind of load with basically any kind of machine unless conditions are really marginal. My own experience with this is from Spitsbergen, not many gaz stations there... Most trips involved at least two jerry cans on a sled. (Although I freak out when I think of how we utterly failed to prepare on some of our trips... whish I then knew what I've learned from this site...)

Most likely, you've already made the decision for no sled. That's OK, it is your choice, a sled would make life a bit easier but it's not impossible. I just want to make sure that you don't make that choice on false assumptions.

Another safety factor that is really important: I assume each rides his own machine - that is a huge safety asset. When (not if, when!) a machine breaks down you can saddle up two on one machine and ride home. It's boring and a pain to ride two on one machine, but it sure beats freezing your butt off...

As for the details of the equipment - I really have nothing to add. I'd say there is really good advise in this thread - kudos to all that has contributed