Four people in a cruiser (even an 80) during the trek would be a very full, roof rack required sort of ride!

Considering the gear need for 7-10 days off-road, two folks per is ideal.
OTOH, I'd love to see four guys (better yet...girls


come up and fill a cruiser to the brim. I suppose since renters would be flying, how much gear can you really bring?

Know that you'll always be taken care of - I'm mean how many axes, welders and

does one group really need?
It all depends on how you're willing to live and what you can count on buying when you get there. I've done remote backpacking treks in the 10 day range. Although I wouldn't be able to put everything I would need for a trek like this in the overhead bin as carry on, I'm pretty sure I could get by with 1 checked bag.
Tent & tarp ~ 8lbs
-40* Wiggy's sleep system ~ 9 lbs
Base clothes 15lbs (way more than I'd ever take backpacking)
Warmth & water layers 12 lbs
Vit Kit, basic cooking utensils, empty canteens ~ 2 lbs
Two big dry bags 1 lb
Pack it all into a wheeled duffle ~ 3lb
=~50 lb checked bag
Carry on the camera kit,

kit and whatever else didn't fit in the 50lb limit on the big bag.
Beg borrow or buy a lawn chair once there. Donate it to anyone who wants it before leaving.
Obviously those flying in won't have camp stoves, tools, fuel, food, beer, liquor, firearms, large water containers, recovery gear, portable showers, awnings, tables, spice racks, etc...
They're going to want/need to do a bit of shopping once there.
As for 4 people 10 days in an 80... I've done that several times. Even with a compressor, foolish amounts of tools and spare parts, fridge, lawn chairs, multiple tents, folding tables, stoves, fuel, four sleep systems, clothing bags and more I've never needed to put stuff on the roof. Granted, I have the 3rd row removed and a cargo barrier and can't see out the back - but it all fits.
So - I could see 4 people in one 80 if they're all limited to less than 75 lbs of personal gear, know what they're getting into and can be friendly with the others.
Meeting 3 strangers and spending 10 days in a vehicle with them in as close to no-where as a person can reasonably expect to get? Now THAT would be an adventure.