Class C and water

How much payload will you have after you load it up with all your stuff ?
That will determine how much water you can carry.

I fill my tank. That's what it is there for! I even drink from it (gasp!)

“We use the facilities in the campgrounds...”

And if there are no facilities? An RVer from Arizona traveling without a full fresh water tank. Interesting.

I only put in above the first or second sensor (I can see my tank as I fill). My wife uses bottled water for drinking and cooking purposes.
We freeze a bunch of smaller water bottles and load the fridge with them at the start of the trip. Later on we can drink them.

Water weighs in at 8lb to the gal and we do not fill the water tank. I put in about 1/2 tank based on the water level meter comes out to about 15 gals. So the weight penalty is not that much plus we only use it for dish and hand washing and the toilet so really not a whole lot needs to be transported particularly if you stay in campgrounds where you can add as needed. We use the facilities in the campgrounds and have never used the bath/shower in any of the units we have had. Put a large ice chest in the tub/shower instead since the refrig is small in most cases. carry about 2 35 unit case of water and a couple of gallon jugs. have never needed more in our travels.

I always fill the fresh water tank, even if I will be camping in a place with hookups. If nothing else, it lets one use the toilet or wash lunch dishes while on the road.

Towing the jeep, assuming you're towing four down or using a dolly, adds little if any weight to the axles, which is what you mainly need to be concerned about. It also goes without saying that, say, fifteen gallons of water in jugs will weigh exactly as much as fifteen gallons of water in the tank. If weight is a big constraint, you could always fill the tank only partly.

You should fill your fresh water tank as it is meant to provide water for washing and the toilet, plus other uses. Shouldn't add too much weight to your overall load. We also haul fresh water jugs or bottled water in our tow behind Jeep so we don't have to worry about water supply in case we are in a CG w/o water or we want to boondock. Sanitize the FW tank with bleach and rinse out the tank before filling for the road trip. Add a little bleach to the tank when you fill it, maybe a half cup for 20-30 gallons.

Lots of beautiful camping sites in the West without potable water...or any water at all. I travel with a full fresh water tank so I can stop anywhere. Fill and dump at every opportunity. Truck stops? Doesn’t sound like fun to me.