Doesn't sound like too much to worry about as the night temps are low but the days warm up. The pressure gauge will freeze fast and once frozen it's broken but cheap to replace, or, just unscrew it and if you need to run the pump get a pipe plug at a plumbing store. 1/4" NPT is the thread. The return fittings talked about are probably just the eyeball retaining rings. Water won't freeze that deep in the pool. I wouldn't worry. Pipes above ground will freeze first so just opening things like the pump basket should let water in the pipes drain to the level of the pool water which is usually below ground level. I use pool noodle foam in the skimmer for ice expansion. If you have a multi-port valve on your filter then put the handle between settings. That opens all ports and aids draining of the pipes. Remember that it takes time and low temps for a good solid freeze. At questionable times I put a plastic bottle of water out somewhere and that gives me some indication of the freeze condition.
That's about all I can think of.
Good Luck.
Al
PS: If power goes out what about things like freezers and refrigerators and the heating system? That's why I have a couple generators and a bunch of gasoline stashed away behind the poolhouse.