I do "all of the above". I travel in many different ways both for business and increasingly for leisure. It's good to always have some breakfast-type food, or whatever floats your boat that can be heated up with a kettle in your luggage as a backup. Alternatively, stock up as soon as you hit town. Yes, after a hard day or after the graveyard shift even pot noodles or pot rice can be strangely appealing.

If I am not in a place with access to a microwave then I also carry a small low-voltage cooking apparatus that is powered by electricity with me and use it very discreetly in the hotel room. Its voltage is so low it does not flip the switch found in many European hotel rooms as any normal item powered by electricity could. Risotto, vegetables, all baked dishes e.g. lasagne or cannelloni, and soup all cook really well in this. It's funny how much more consoling and restoring a hot meal in your hotel room can be when you are on the road.