@Joelle43 have you considered portable air-conditioners for the bedrooms? The upside is they're generally cheaper and you can remove them (and win back the space) in winter.
The downside is they collect water that you have to get rid of. So you either have to connect them to plumbing (which may be possible depending on the layout of the bedroom in relation to the bathroom outflow pipes), or have an outlet that runs the water outdoors, or the guests will just have to empty the tank every now and again if they want the aircon to keep working!
The problem with any machine that needs attention, is that it may beep loudly in the middle of the night and wake up the guests to let them know the tank is full. So you'll either need a model that won't do this (perhaps one with a proper night mode), or you need to let the water out somehow to avoid the tank filling up.
You've said before that you like to overthink things, so I'm just making sure you keep busy 😀