Grrr... whats that smell??

[SwissXC90]

Drove home today after being away overnight, car was parked overnight outside on a hill, parking brake firmly on, in about -3°C to 0°C outside temperature.

30min drive home, nothing unusual noticed.
Parked in the garage, unloaded stuff and thought: what's that smell?
Hot, burning, like clutch or brakes... but I hadn't been driving hard, and my Auto D5 has no clutch...
Smelt it on drivers side.

Brakes?
First thing I did was the hand temperature test on the wheels: left rear warm, all others cool.

Got the old thermometer gun: front wheels 12 degrees, brake discs 8 degrees. Ambient in the garage is 9 degrees.
Rear right 9 degrees wheel and disc.
Rear left 22 degrees. !!!!

Damn, Brake shoes binding, probably parking brakes.

I stomped on the brakes a few times, parking brake as well, to move it and maybe free it.
Did the roll test: my car park has a slight downhill and the car will roll slightly backwards when the brakes are off - OK.

One more thing to keep an eye on.
As well as weeping power steering.
And front right brakes squeaking sometimes.
And the mysterious rotational squeak from I think the front right wheel when brakes are off.
And maybe (??) transmission problems developing (I hope like heck not... gonna try a reset adaptations when I get the car back).

Car's going to Volvo for a week or 2 tomorrow (long story, it's coming, stay tuned). I'll be getting a loaner for a couple of weeks. Be interesting to see what.
Might trigger me to get another car....

[Tannaton]

More likely piston seized in the caliper I think - it happened to mine, just stripped it, cleaned it, reassembled it with all original seals etc. and it's been fine since (22k miles).