Unless your kids magically stay the same size, just suck it up and get a 4x4 domestic van. As they grow, you'll be much happier in the long run. I can easily fill my 4runner for a weekend trip for 2 adults. Hard to imagine how we'd ever pack it in there if we had 5 people.
The OP has 3 kids (the oldest being 6). The 4runner can easily accommodate 2 adults and 3 kids. Honestly, 4 normal-sized adults and 1 smaller adult can fit easily as well.
If his kids are that young, I think the OP has many years of usage before space really becomes an issue. And by the point, he'll likely be looking for a new vehicle anyway.
