OK, I'm only guessing, but I assume that the Q16 means a 16K Hitch, whether you buy now or later, I would go with a higher rated hitch because as others have commented you may have an entirely different and much heavier RV by retirement time.
2018 Chevy 3500HD High Country Crew Cab DRW, D/A, 2016 Redwood 39MB, Dual AC, Fireplace, Sleep #Bed, Auto Sat Dish, Stack Washer/Dryer, Auto Level Sys, Disk Brakes, Onan Gen, 17.5" "H" tires, MORryde Pin & IS, Comfort Ride, Dual Awnings, Full Body Paint