That time during my holiday, I brought along my Tiger food jar... Coz during the buffet spread, got porridge. So we scoop some porridge into the jar which can keep the porridge warm for long time.
So his lunch is porridge, then dinner is cereal. Or you can just feed him porridge during the breakfast buffet and then store some for lunch then just do milk for dinner. Still make up the 2 meals of porridge
We also brought the Pigeon porridge to mix with the white porridge for taste.
If you're staying in an ok hotel, the breakfast buffet should have quite a spread including plain congee...