Don’t think it would work, i.e transferring apps to and from dedicated servers, does not come without some bugs. And to do it for one day only, it’s not worth the hassle. I think a better option would be a redirect for any outages. At least then we have some control of what the customer sees at the time.
I find that the team at bubble are extremely responsive to issues that affect the main cluster. In my experience far more responsive than Google.
Dedicated servers I found are useful if you want to create many sub-applications from a main application. Separating database, domain, main settings for each individual sub-app, will allow you to scale faster and to a larger number of users with the added bonus of you controlling upgrades. Usually perfect for data intensive business applications.