Think about aging in place. One day a wheelchair might need to fit through those doors. You need to get > 28 in if you can. Def don't go for 24".

Thank you J T. This is a bathroom on the second floor of the house, so probably wouldn't be appropriate for an older person. We're in our mid thirties, for reference.

Would still go for wider door if you can

Go for the 28 inch door. You won't need to trim much, if any, by the time you remove the drywall to put in the jamb. If you already have the door, you might be able to use thinner jamb material to a bit more width. Otherwise you will need to make the opening larger to install a prehung door. Are you hiring someone to install the door?

I was hoping to do it myself!

Does your rough opening of 28.5" take into account that you will be removing drywall?

Definitely don't do the double doors.

No, I didn't account for removing the drywall.

Then that's not your rough opening. If the opening is square and plumb, you have room for the 28" door.

Which side will get the hinges and will the door open into the bathroom or the bedroom? If this is the beginning of your DIY career, you are not picking a typical beginner project.

I am 75 and can still quite easily climb stairs but your issue needs to have you post a to scale floor plan and this was a pretty typical 70s idea and besrt redone to make a nice bathroom space so I would not spend a lot on any 1/2 way work so put the door that you have with a bit of trim to fit and save until you can bring this into this century