Last time I saw a laptop-randomly-sleeping-every-few-minutes issue, it was the magnetic wrist band of a schmancy new smartwatch triggering the magnetic lid-closed sensor in the palmrest.
Yeah changing one tyre on its own is usually A Bad Idea, especially if the others are worn a little. You don't want to chuck some random tyre on one corner in isolation, all tyres are definitely not equal.
Different tread patterns or compounds side-to-side is a HUGE handling/safety no-no, and having one worn and one new tyre on the driven wheels especially (or anywhere if the car is AWD) can destroy diffs or AWD clutch packs.
Two-wheel-drive car, you should be able to get away with only replacing the front or rears as a pair and you should be golden.
I'm tempted to change all our digital signage to just giant countdowns...