Please do NOT come to my state and stealth dump.
We are a family of 3 and often have a 4th and, rookie season aside, almost never have a tank mgmt issue. What is the capacity of your gray tank?
Conserve your gray water:
Use disposable/recyclable dishes.
Toothbrushing etc done in park bath houses
Wash dishes at community sink, if available.
Pre-cook meals ahead of time that might be messy and/or require a lot of cleanup to prepare.
Train your kids. LOL.
A lot of things like above you can do to stretch the grey tank.
No joke, we often have to run some water into grey to get it full for dumping. Even after a 3-4 day trip.
FL state parks don't offer portable sewage service.