* Like Tony did, I left my mattress rolled-up, and inserted it easily thru my 26" wide door. Later, I added a second one to lay on top of the other (both Ikea twins). However, during several revisions/alterations I had to get my wife to help maneuever them in and out (though 32" high, it is angled at the top, and the door has an overhead shelf just above it, so it needed some persuasion).
* After several changes in my sleeping (always just me inside), I figured that 1-2 foam mattresses, and sheets, blankets, and comforters were just too much of a hassle to clean & straighten-up, I switched over to using a quarter-fold foam mattress (with integral cover), and two Coleman sleeping bags (one for 20 degree weather, the other for 50 degree weather).
I did retain the two excellent king-size Serta? pillows from before, though.* This new arrangement is quite sufficient for me, easier to maintain, convertible to a semi-chair, and the firm mattress suits my bad back better.
The two Ikea mattresses were bought to try to entice my wife to use the camper sometime, but she opted out anyway.

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