We are snow birders and one of our neighbors has one attached to their window and have no problems at all.
If it is attached to a window, I doubt if you would have any problem with mice, since they can't climb on glass.
I feed the birds when we are at home, and keep the seeds in a large plastic trash barrel in my work shop. One time I left the cover off overnight and was greeted with a mouse down inside the barrel trying to climb up the slippery side. It could not do it
I think it is a neat idea and say -go for it !
Jack L