Here comes an unusual over-nighting tipp for the overlander: Hotels. If you have not just started your trip yesterday or if you are not all just nature and like visiting a city once in a while I am sure you have run into that. No campground, not friends in town, street or free camping not possible or simply not safe, so you might exceptionally check into a Hotel, kind of have to.
I think there are almost more hotel booking web pages than hotels. Do you know hotwire.com? My friends from Bonaire who run and own hotels themselves have focused my attention on this web-page. The principal is simple, you can not chose the hotel, meaning you chose an area in a city and you'll see the price, amenities (including information about parking) etc, the price is supposed to be guaranteed the best price available, which I found to be correct in most cases. Once you book and pay you will see the hotel where you are staying, get an address and a booking confirmation code. With that your show-up on the drive way respectively at the reception desk of the hotel and off you go.
Especially in the US there are many, many hotels offered. I have stayed at 4 or even 5 star locations in city centers for below USD 50/night or at Hotels of a kind of Holiday Inn standard below USD 30/night. In more expensive US states like CA or FL sometimes I found campgrounds to be more expensive than hotwire hotels. Of course I do prefer to sleep in the blue truck and to be out in the nature, but for those occasions where it simply might not be safe or not possible, I like hotwire, they have offers in most larger cities not just in the US also in many mexican and central and south american cities. Of course you can get a dorm bed in a Hostal for less, but parking is an issue at most hostals. And be honest, when you are travelling for months or years, once in while it is nice to crawl under those white sheets, or when that little bug got you it is such a luxury to have your own clean pot to sit on, have A/C in some hot tropical city and to know you and your car are safe.