I have a 40 gallon fresh water tank. We took 2 quick showers, a few toilet uses and a small dish washing and my tank was showing empty. What is the average dry camp water use? Seems to us, 40 gallons ...
Also, you may be able to monitor your actual usage if you can see the fresh water tank. On our MH we can see it under the jack knife couch. On our old TT, there was an access panel.