Thanks to everyone who responded to my question. Those were all good reasons to keep the phone nearby.
To the landline question: We have one in the bedroom, but the ringer is off (and has been for decades).
Maybe my situation isn’t as common as I thought, but there isn’t anyone I need to interact with for medical reasons (like Thelmalou’s mom), and no kids are close enough that we could help in an emergency. Since my cellphone insists on bleeping and blorping whenever it thinks something interesting has happened, I banish it from anywhere I need peace. That includes watching movies, reading, and sleeping. That’s why I was taken aback to discover people bring the annoying things into their bed at night.