I wonder if you could do a 2 browser trick.....like before modify was a thing.
So, modify your existing res. for the full length of stay you want, select your room, and then it will say something like you don't have enough points even with banking and borrowing, but there is a proceed button that takes you to the next screen anyway and when you get to that switch over to the other browser and cancel your other studio....
I don't know what you do from there to get it to refresh....
Just a thought. Have no idea if it would work.
Maybe someone with some points to play with (but not too many) could try this out...