Huh, that's an interesting thing to think about. Does Asterion actually prefer a relatively cramped room due to his own tastes? For me though, I think Asterion would like larger personal quarters for himself. In his mortal life, he slept on the Cretan palace and the labyrinth. Asterion probably has fond memories of his family's palace and a large room for royalty. Likewise, I think the labyrinth also provided a large space for him to sleep in. I'm basing this on the lore tablets, where him and his visitors slept within the vicinity of Hera's fire-shrine. I think that room would be pretty big, at least bigger than his present accomodations anyway. I would guess that the only reason Asterion had such a small room is to intentionally make himself comparatively insignificant to the master. In his monologues and musings, he admits doing things to that effect. But if he did prefer the present room, it's may be conditioned into him by centuries of subservience or clining onto the positive memories-- mementos and the like (his room has wooden carvings over the years).
On another note, this seems like a personal project rather than RD for the hotel and its customers. After all, this concerns only Asterion and the master (to a small degree).