I came to the truck camper world from the toy hauler side and was spoiled with a 10 gallon hot water heater, dual 75 gallon fresh tanks and dual 50 gallon waste tanks, so even there it was easy to over fill your waste unless you managed what went outside or carried a tote for overflow. It was an adjustment for us, so we chose the truck campers that had greatest capacities and compensated with additional tanks in our enclosed trailer. I remember looking at the Northern Lite 8-11 and really loving the quality, but was put off by the small 30+ gallon fresh tank and waste tanks so small the combined capacity was less than just the gray on other campers.
I would guess only 1/3 of the nights we camp are without hookups. Of those boon docking nights only about a week per year are we in a location where we can use the external shower to divert gray water. We currently comfortably boon dock for three nights without worrying about usage - Next month we are going to try to double our boon docking with only onboard tanks and see how long we can go.