Rollaway bed mattresses are excellent if used on floor. Most are about 8" thick so not too bad even for a back sleeper if placed on floor but can take the cot too if you want. Can use truck tie down straps that ratchet hook to tie up mattress to put in back of car. Cot is much easier to transport than rollaway bed.
Love this little table/desk. Is very sturdy and height adjustable. It is half the price, around $20, at Lowes and Menards btw. LINK:
https://www.amazon.com/Personal-Adju...ng+table&psc=1
I use camping cloth folding chairs. I really don't have a good review yet of any of these...Cheap is a bit unpleasant if you work online all day it it. Can pay to get cheap desk chair at Walmart, assemble it and just enjoy as investment if you work online. Can work nicely from the desk/table I recommended above.
I do transport a microwave and basic-mess kit for kitchen with skillet & bigger sauce pan, few dishes and few basic $$$ store items but this could easily be handled with a trip to thrift store. Sadly, I find microwaves to be in short supply at most Dollar Generals and not all rural locations even offer a Walmart so can be helpful to bring along microwave as I have bad skin allergies and microwaving meals is better for my skin.
Always found a local small town Sears store for mattresses and used furniture business that will deliver if you get multiple pieces. Is good investment if you are staying 6 months+ and cheaper than rental furniture places.