Boondocking: limiting factors (gray and black tanks)
If you would love to do a camping trip like the picture above and just disconnect from the globe you can with a travel trailer or RV. The main thing is you will be limited to the amount of time you can stay without any hookups. This type of camping is called Boondocking or Dry Camping. If you want to Boondock you can, you just need to be very minimalist and know your limitations. Some of the biggest limitations are going to be water and the tanks.
For power, you can use the battery and be careful what you run as well as add solar panels to trickle charge and give yourself a little extra time but you will be limited to what you can use for how long. The other option is a generator that can power your RV but you are also limited to the time you can use it depending on gas and how loud it can get.
With gray and black tanks you are limited to your dumping options.
What tanks are included in an RV/ Travel Trailer?
Most RV and travel trailers come with a Black tank for all the sewer waste and a gray tank for all the other drains. Many will have a freshwater tank to hold all the water you will be able to use. This tank can be refilled with multiple sources of water and can be somewhat easy to refill. The biggest limiting factors are the gray and black tanks. Depending on where you stay the gray tank can be the biggest limiter while others its the black tank.
Freshwater tank
This is the water available for drinking and use in the shower, sinks, toilet flushes.
Black tank
Toilet water and should only be dumped in sewer hookups for obvious reasons.
Gray tank
Shower and sink water (there should be no food dumped in these pipes). This is the water that will fill up the tank rather quickly. We have a 30-gallon tank and will fill it up between 2-3 days of sink use and a few showers. Depending on where you are staying you might be able to dump this around as it is mostly shower and sink water but not all locations allow dumping.
Final thoughts:
If you like the idea of disconnecting and Boondocking it is very possible with an RV or travel trailer as long as you know the location, their rules for dumping, and knowing what your limiting factors are going to be. I would recommend a trial 1-2 day trip (Preferably at a site with power and full hookup and testing out how much water and power you consume before starting on longer journeys and building up to what you and your rig can handle. If you notice you fill up quickly you can just dump and keep testing adjusting your consumption.
Resources:
Boondocking: The Complete Guide to Free Camping (Almost) Anywhere