I’d much rather have a colder coffee than something too hot. I would say that over 50-52 C is too hot.
In times gone by, way before first, second or third waves, coffee bars in Italy were esteemed for their skill in serving you an espresso or a cappuccino that could be drunk immediately, as they weren’t too hot. Never brought a thermometer around, but my guess is that we are talking mid-40s.
I’d be tempted to serve your guest with a freshly boiled kettle, a nice tub of instant coffee, and sugar, milk and cinnamon powder to taste… 😉
If you can’t bring yourself to my level of rudeness, I think an Americano in a heavily pre-heated thick cup may just about do the trick.