[bushpilot]

Ours are 2x 110g fresh (220 total) and 2x 55g black & gray (110 total).
220 gallons seems plenty for fresh (i sure as heck wouldn't want to run out of fresh water).

I (try to) only fill our fresh water tanks from known reliable sources (our house spigot). but we do use the park water when we have it (we just don't drink from it & we generally don't drink from our own tanks....always have bottled water). If were in a park (connected to city water), we turn the water supply off (via 1/4 turn hose/valve) when we leave the coach - just to avoid the chance of a flood from a busted water line or something) while were gone.

I filled the black tank once (occasional use while on my in-laws curb for 6 weeks) - i had a tank sensor wire break and didn't realize the tank was full...didnt have a problem but i would have taken action to drain it sooner.

I too wish the tanks were larger (but for the life of me as i think about it, i don't know why) - we've never filled the gray (or black) even on a long race weekend with several guys taking showers.

The gray tank is the least of our worries, if it gets (near) full, you can always just leach off the gray water into the soil (under the cover of darkness) - after all its just soapy...the trees and grass love it (and the soap can help to minimize bugs).

We're not full-timers & we don't stay in one place very long (unless its my MIL's).
we (mostly) use our coach like a station wagon, long road trips & occasional camping - we've never had a problem finding a dump station at some interstate rest area or camping world (free) & if necessary we could always pay to dump it at pilot/flying j truck stops.

our storage lot has a dump tank (and wash bay) - so we generally just bring home what we have and i dump & wash the tanks before i put it in our garage.