There's traincrew depots at Buxton and Pwllheli, as well as other minor termini such as Tweedbank, Mallaig and Stranraer.Buxton definitely stables at least two units overnight. I should know, I've woken up there on the last train of the day, and had to stay in a hotel!
I begged the crew to take me back down the hill but they told me they lived there.
One question, is it normal for crew to live at these extreme points (thinking especially about the aforementioned Pwllheli) or are they ever put-up in hotels for the night?
Correct. Platforms 2, 3 & 4 all take units when the centre roads and Fishdock are full, sometimes when they are not. It's about all Platform 2 is good for now unless they start some silly 150 operated Sheffield-Dore peak extras.I believe that there are units stores at Sheffield Station on Platform 8 & on the lines in between platforms overnight.
Occasionally they end up with units stabled in both platforms. Quite a few times I've been on overnight infrastructure monitoring trains which have had to reverse short of the platforms because they're both occupiedTwo Class 333s will be kept on one platform at Ilkley overnight to form the first and second trains of the day.

A 5 car 165 is still stabled there overnight now, the exception being on strike days where multiple sets are stabled insteadLondon Marylebone?
I've never been there late but given daytime a number of sets are, or at least back pre-2020 were, in the platforms so a long walk to the units in service I would be surprised if several are not there overnight.
When Waterloo first opened there were multiple mini turntables (31 or there about), between the arrival and departure platforms, plus a number of others. The very last one to be removed (I believe) was situated on the departure platform road, near to where the 'crows nest' signal box was. Ref: Monographs various as published by The 'South Western Circle'.Back to the early days, the great train sheds at termini were there to service trains. Equipped with turntables to move the light vehicles between the tracks. Dont know if its an urban myth but its said the transepts at Paddington were there to house traversers.