With 5 of you and your golden, I think a TT is better over a 5er. Think of all the extra gear you'll be able to haul with the truck bed still available. With a 350, I doubt that cargo carry capacity will be too big of an issue.
We have graduated from tents, to a pup, to our current HTT where we expect to stay for a while. The eventual plan is to start full timing, and THAT's when we'll buy our first 5er. Hopefully gently used from another golden ager getting off the road. I certainly don't regret any of our choices, they have all been appropriate to our needs and stage at the time.
2011 Jayco X19H (purchased 2015)
2008 Jayco 1007 PUP (purchased new, traded for the X19)
2012 Chev Traverse LT with TP