Best lightweight options for popups travelling with minivan?

I pull an 8 foot box Starcraft easily with a 2010 Town and Country mini van. Most of the time the van is loaded down with firewood, bikes, wife and two kids, two coolers, a canopy, and other gear. I've been up some moderate mountains with no issues whatsoever.

I did add a transmission cooler to the van and I'm careful to gear down when going down steepish hills. I think if you go with an 8 foot box pop-up, even with fridge, furnace, microwave, etc. you'd be perfectly fine.