
Exped
MegaMat Series
Car camping comfort champ, but some side sleepers find it thin.

Running these analyses costs money. Buy through my links to help keep lights on! I may get a small commission.
I ordered the Therm-a-Rest LuxuryMap Self-Inflating Foam Camping Sleeping Pad, Large - 25 x 77 Inches - from Amazon. It's warm and very comfortable. Very important to be insulating on the bottom, especially as temps start dropping.
Two separate Thermarest Mondoking XLs side by side - different air pressures - no waterbed affect when one of us moves/rolls over. Kelty doublewide sleep system (bag).
Megamat Ultra and the Thermarest Neoloft are comparables. Def not ultralight but I use the Thermarest on backpacking trips, not thru-hikes, and love it. I'm a big guy and the Thermarest is comparable to my MondoKing and Exped MegaMat Duo. The Ultra will work well for you.
Thermarest MondoKing, and if too big for storage go Thermarest Neoloft.
We also have just two car camping pads side by side! Enough for snuggles without disturbing each other as much. We have Mondo King pads/mattresses. Not sure if they still make them but feel like they were less expensive than the Expeds seem. And option to still use it for a solo trip.
I've used my thermarest Mondoking for YEARS. Even when I have a visitor they use it. It's expensive, but the best quality I've seen yet (I've gone through a few) it's so comfortable I look forward to camping and sleeping on it. Definitely not small, when deflated and rolled up it's the same size as my ten but 11/10 recommend for cozy comfy nights
I've used a 3P and a 4p with my bf. It was the perfect size for me in my msr elixer 3. My bf and I got the sea to summit version in a double for both of us to use and it had leaks within the first two weeks so I'm a big fan of how well my thermarest has been holding up
We sleep on two Mondo Thermarest pads strapped together. They’re 5” thick and wider than conventional Thermarests. Very stable and comfortable to sleep on.

Exped
MegaMat Series
Car camping comfort champ, but some side sleepers find it thin.

Exped
Ultra Series
Lightweight side-sleeper comfort, but a bit pricey and bulky.

NEMO
Tensor Series
Ultralight side-sleeper comfort, but slippery and prone to leaks.

Big Agnes
Rapide SL Insulated Sleeping Pad
Comfortable with side rails, but heavy and warmth claims disputed.

Therm-a-Rest
NeoLoft™ Sleeping Pad
Very comfortable, good service, but heavy and bulky for backpacking.

Ranked #1
Exped - MegaMat Series

Ranked #1
Exped - MegaMat Series

Ranked #1
Exped - MegaMat Series

Ranked #1
Exped - MegaMat Series

Ranked #1
Therm-a-Rest - NeoAir Xtherm Series