How much money do you think you are going to be able to pull in?
If you just want to be out in the wilderness because you prefer not to be around people that's fine but when you bring up walmart for more than a quick overnight as you are going from point A to B, that suggests money is not so good.
If you boondock all the time, not only do you need to figure out internet but also, sewer, water, electricity, groceries and a number of other things. They can certainly be done but they add a layer of hassle.
If you really are making a bit of money, staying in RV parks addresses some of the issues. I wouldn't count on the wifi but it does solve the other utility issues. If you look at monthly rates, they are often quite reasonable with $250-600/month not uncommon. If that's tough to swing, I would argue that you are tight on budget and what will happen when you come up against a big expense.
The other big complication for early retirement is health insurance. If you make next to nothing, you do get a big subsidy thru obamacare but also keep an eye on where you can get service. If you are constantly dealing with out of area providers, that can add quite a bit to the cost. If you actually are making decent money, insurance takes a big bite out of it.
As mentioned, get a good idea now of what your data consumption will look like. The unlimited cellular isn't really unlimited. It's better than 5-10yrs ago but it's not an all you can eat buffet of data like a landline based ISP.
