Trailers are like a lot of toys in life. Once you've had one, you want more. Some folks downsize, but usually it's the other way around. Especially if family size increases or kid's friends start tagging along.
Given that, you may want to consider a bigger tow vehicle. If you're upgrading anyway, a 2500/250 isn't really much more money than a 1500/150. But much more capable.
Don't discount hybrids. You can gain a ton of extra sleeping space with them. Space that's not used on a particular trip, is excellent storage space. Either that, or look into bunkhouse models.