If it was the other way around, Mizuki-san would have been Sanaelated.
He makes the hotel arrangements and should thus know both his application status and accordingly required hotel nights, so it's not as likely. But yeah, if he booked a room for a night when he knew they wouldn't be needing it, he'd earn a Sanaelation.
I may have missed it buy why does she "control" his eating habits again?
Because when unsupervised, he tends to eat too much (sometimes purely at the goading of others, known collectively as the System), and often of junk food, and she cares about him being healthy. This tendency is surely exaggerated in his strips for comedic purposes, but it's still based on true stories.
Eh?I forgot to apply!♡To make up for it, you can eat whatever you like today.
Touhou Was on the 2nd Day
The next day, on the first day of Kanazawa Joint Festivals...Today's Kan-Colle's day, so you'll be there, won't you, Sanae.So today, I'd like to go to Yamanaka Onsen!Sorryyy!No, I won't.If you weren't taking part in the con, then we could've saved a night's hotel expenses and yet...and yet...