If you have the owner’s manual for your 4 cyl VW, check both the tow section and the brake section. Usually there's a tiny little notation in the brake section that limits you to 1000 lbs unless the trailer has its own brakes. It's probably do-able with care....it's easy to go over your weight limits...ask me how I know. (as I sweat loosing excess by trimming wood everywhere I can!)
I'd put the kids on a sliding upper bunk like Alfred is doing and do your cooking at the picnic table. That way, you all get a mattress and a warm, safe bed plus you would probably still have a small area at the bottom back of your teardrop where you can store your kitchen supplies.
A Rimple or Benroy might be a good style because one of those would give you the most usable space. Also, there are already Generic Benroy plans that you can click on at the top. You'd just have to tweak them a little.