I am like you, we camped all summer 1 week away home 7-10 days then away again.
I filled the fresh at the camp site and usually by the weekend 7 days it was very low. I would keep it in there for the trip home incase we needed to use the washroom then drain at home.
Sometimes I would leave and drain enroute to the next trip
So a mixed bag.
I am on a clean well so no chlorine in my home water so I don't leave that in for more than a week or two
Stella the 2000 30ft Excella/Classic - Tow Vehicle - 2012 Mercedes Benz GL350d - CanAmRv.ca Reinforcement and EZ-Lift WD with 2 Anti Sway Bars. Back Up tow vehicle 2005 Ford F150 Lariat 367,000Kms 5.4L