We have three kids plus at least one more and two adults (although DS16's shoes are the biggest at size 13!). We have the 3170 and also struggle with shoe storage (plus coats) for five to seven people.
Put a metal shoe organizer (basically two baskets, one on top of the other) at the top of the stairs behind the bench. Everyone throws their shoes in there with no organization. I just gave up; at least there's no tripping. DS16's shoes are too long, so he puts them on the floor next to the basket.
I've considered sticking shoes inside the pantry that's on the way out the door (next to the fridge) but kids probably won't close the pantry doors.
Have also considered hanging a cloth or plastic shoe organizer on the outside of the bathroom door for the "extra" pair of shoes. Currently have an over-the-door basket for gloves, hats and other cold-weather gear with hooks for coats and raincoats. (We camp early and late in the year in Michigan).
Also considered using Command hooks to hang a cloth shoe organizer with pockets on the back of the aforementioned dining room bench. Certainly accessible on the way in and out. I hung one from the wall with the Command hooks when we had a TT and the kids surprised me and used the thing. It had enough pockets that we also stuck dog leashes in there. You may have to trim the last one or two rows of pockets because an organizer may be too long for that spot.
Let us know what you do end up doing.
Owners of a 2013 Sunseeker 3170 Class C beauty. We travel with two shih tzu, a leonberger and, oh, yeah, two teens and a 6-year-old.