I have no opinion on coffee temperature - I've never had a sample that I enjoyed, hot, cold or reheated - but my wife has the same problem depicted in the original post. I got her some rechargeable heated mugs and now her drinks stay warm for a lot longer.
I don't know whether this is considered preferable to microwaving, but it does seem more convenient.
Tomorrow me is gonna pretty stoked for triple-coffee day! Think about how much they're gonna get done!!!! (I might sneak in a nap this afternoon in anticipation, lol)
All you need is a french press and they're pretty cheap. You just put the coffee and water in the fridge overnight 8-10h and it's good by morning. Way better than regular coffee imo. I'm sure there's snobbier ways to make cold brew but I value simplicity
Gonna second the French Press in the Fridge method. It's the one that works best for me; cleanup is pretty easy, and the only problem is trying to fit it in the fridge without fully depressing the plunger.
The forgotten coffee problem was my main reason for switching to oatmilk. If it stands around uncooled with cow milk for too long it grosses me out, but oatmilk isn't as volatile so I don't mind drinking yesterday's coffee.