"the PHX landing site will be in 24/7 darkness within a few months. When it landed, it was 24/7 daylight. We're now in that transition phase in the drop off from about 3kwhr/sol to zero. At some point on that slope, the arrays no longer generate enough energy to keep the avionics and battery warm, and then it's game over."

I understand some of reasons a human body can't be returned to life after being frozen. But what prevents a machine from being brought back to life after being frozen.

Being in the very long Martian winter will have one advantage- no thermal cycling.

"The Martian arctic is a nasty nasty place, and a brutal engineering challenge."

But it also has very long periods of constant sunlight and during this period of time little thermal cycling.

I would say anywhere on Mars is nasty place and difficult in terms of engineering.
And it seems that having a solar array which points towards the sun would have significant advantages as compared to more equatorial locations