DavecUK Exactly. That’s the problem with all portables, is it not?
I think it is a good thinking, but needs to evolve. May be, a thermal flask concept to retain the temperature or a portable heating element. In the case of latter, we would be lugging the battery.
We prefer a mess free travel either for business or pleasure. We don’t drink coffee, if we don’t find any decent shop.
I will also be a little wary of carrying these portable devices for flights! 😁