I have the same challenge in front of me with my very young children, but we have no aspirations of going south of the border (north of the Red River, maybe!). The answer for us is a Suburban and a tent. There are some snazzy tents out there these days if you don't have to have expedition-bling or hard sides on your abode.
How minimalist do you want to be? What things are you not going to compromise on?
How 'bout a crew cab truck with a hard-sided camper in the bed?
'07 Suburban for wifey to taxi the kids in
Lifted '05 Unlimited Rubicon for sitting in the garage since we had kids
2010 Scott SUB40 commuter bicycle for getting back and forth to work
If you wish to hear God laugh, tell Him your plans.