The concept might work, but I've never seen a regular hotel that provides a meaningful set of dishes. So if you made oatmeal, you'd have to do it in a coffee cup and try to drink it, or carry cutlery with it.

TBH, that's the perk I want in a hotel room-- a couple of sets of plastic silverware, so I can just bring back a takeaway (or leftovers) at the end of the day and be able to eat it without some comical scenario like trying to use plastic straws as chopsticks or smashing my face into a bowl of Pad Thai.