I’ve lived a…less-homed life than most, so I’m glad to be in a thread where I can give some advice as somebody who’s done most of these. I’ll sum up my thoughts on some of these modes in worst to best order:
Car living: rough - awful sleep, no bed or comfort, difficult to stay warm without running the engine, the windows steam up so it’s obvious you’re sleeping in there, not a lot of room for your stuff. No bathroom, kitchen, etc. On a 1-10 scale with 1 being least desirable and 10 living comfortably in the home of your dreams, car living is a 2. It beats literally living on the streets, but that’s about it.
Van living: Just like a car, but with a bed and more space. Same shortcomings otherwise. 3 out of 10.
Tent living: Depending on the locale, this can be terrible or it can be great. The “great” case requires that it be basically semi-permanent, in a nice location, with amenities like showers nearby (a house that you’re paying “tent rent” to, a campsite with showers and grills like ZonexandScout mentioned, or other similar options), but if you have those things, it can actually be a decent option. More space for your stuff, more comfortable sleeping - heck, you can even get an air mattress if the tent’s big enough. I’d give this a 5 out of 10.
If you’re mobile and need to move around, tent living sucks. All the downsides of car/van with less protection and mobility, probably a 2 out of 10, maybe even a 1 out of 10.
RV or boat living: At last! The queen / king of mobile living! If you’re used to camping or living in a car/van, living in an RV will seem like you’ve been transported to a magical Shangri-la of amenities, privacy, and luxury. You have a real bed - often several to choose from. You have a refrigerator and stove and microwave. You have AC and heat! You have a toilet right there!! There’s no doubt about it, living in an RV beats the crap out of the other options for amenities. An RV is a solid 7 out of 10.
The only problem, as alluded to by Broomstick is parking and fuel bills if you want to drive it around a lot. RV’s are big and awkward, and RV parks suck and charge a lot in any even halfway nice area. In or near cities, you might as well get a cheap apartment, because RV parks charge enough that $(small apartment rent in city X) is how much you’ll be paying just to park your RV in their crappy trailer park for a month.
You used to be able to park in Walmart parking lots free for a few nights in a row in your RV without being hassled, I’m not sure if they still do that. If you do and there’s enough Walmart’s nearby, I guess you could do some sort of rotation, but you’ll still have to stop at RV parks once every week or two to dump your tanks and take on fresh water.
The ideal RV use case is if you have a good friends / family network where you can park your RV at their house for a week at a time that you can rotate around in. Throw in some campsites and national and state parks you visit regularly and there’s a real nice lifestyle!
So if you have the choice and the urge for mobile living, RV is definitely the best option you’ve listed, and how good it is is highly dependent on what your employment and geographical needs are. If you need to be near a large city most of the year for work, parking will be your biggest headache (but on the plus side, you don’t need to worry about spending a lot on gas). But if you can get your parking sorted, either via rotation or paying somebody a nominal rent to park on their land / driveway, the RV kicks the crap out of living in a van, car, or tent.
Hotel / consulting living: If you’re savvy with credit cards and points, if you have an expense account at least part of the time, or some combination of these things, you can live cheaper than prevailing market rent in hotels. I’ve done it, and know others currently doing it, so know it’s possible. It requires a lot of time shopping for deals, paying attention to points, getting the right credit cards and sign-up bonuses, and ideally your work paying for at least part of your hotel stays, but you can actually live inside in real rooms cheaply if you’ve got these things in the right mix.
Hotel living has the same downsides of all the other modes - you’ve got to travel light and not own much, you’ve got to get your mail forwarded or sent to family, you’ve got to change locations frequently, but in terms of amenities a hotel beats an RV because you never have to empty dump tanks, you never have to repair stuff, and there’s no worries about gas or parking. Hotel living is a solid 8 out of 10.
But wait, there’s an option for cheap living you haven’t considered!
Living overseas: Living in a low cost of living country with first-world level income (even if only retirement or Social Security income) is the ultimate cheap living option.
In SE Asia, you can live in a nice house right on the beach, have a cook, maid, and driver, and eat top-shelf fresh seafood for every meal and your expenses will still be under $2k a month. Want to cut your expenses lower than that? Just take off some of those amenities, you can live on hundreds a month if you cut things to the bone, and there’s millions of folks who do live on hundreds a month (or less) over there. SE Asia isn’t the only option either - I know people do this in Central America, India, and a number of other low cost of living countries.
Obviously this option requires passive income, retirement income, or a job you can work remotely, so again, highly dependent on your employment and geographical needs. But this is a 9 or 10 out of 10 “cheap living” option if you can swing it - barely any compromises, and living well while being kind to your bank balance, so I thought I’d put it out there as a potential option to consider.