My hospital was affected by the big Microsoft update fiasco a while back and one of the key lessons for me was how awesome it would be to stage or split updates. Like maybe don't update all machines, CTs, MRIs, etc at the exact same time. Do a 1/2 or something. There are arguments against that probably, but it was hell for us. I imagine servers could have something similar if you're willing to bear the cost of that uptime.