Preparing before you leave is definitely the way to go.
My brother and I were part of a group hunting trip to the Cape a few years back and the difference in cooking times between the groups who pre-packaged/froze/vac-packed stuff and those who didn't on most nights could be measured in hours!
But, don't freeze too well if it's for the first night. On a weekend trip to Charlie Moreland the year before last, we made a double batch of spag bol about half a week before the trip: half for dinner, half in the bottom of the chest freezer for the trip.
Forgot to let it defrost on the drive to camp. A full set up in light rain was not long enough to melt the frozen block of bolognaise sauce in a saucepan over a 3 ring burner. We sat around for another half hour before it was ready!
We normally do spag bol (as above but not rock solid
),
chicken curry and rice (fry chicken and onion, jar of sauce, tin of coconut cream, and rice),
a pasta pack or rice pack with some kind of protein and frozen veg thrown in,
or something between soup and pasta carbonara based on a tin of cream of mushroom soup and a tin of tuna.
Cheers!
Jono.