Boon docking or remote camp sites generally, at least in the far west means National Forest, BLM, or State parks. All of which usually limit your stay to 14 days. And many of them will not have good cell service. So, to have access to reliable cell service is going to mean established private RV parks. Those almost always offer monthly rental rates. To know for sure you would need to either call or email parks and ask. Also, lots of private parks will require a background investigation before they allow you in for long term.
Around here the background check is like 35 dollars and monthly rates are between 400 and 500 dollars for decent parks, plus electricity, which is metered.
How much money do you have in the bank to put down on an RV? Bigger down payment means lower lower amount you would have to borrow. But regardless fewer places will finance used RVs than new. Depending on how much you want to spend, in your case a new RV might be a better option.
