go for it, you may not even need to mess with the nut.
the ones under the string tree(s) will not be a problem at all, the lowest string will have plenty of angle and also not be a problem, it'll just be about the second-to-last string if it's not held down by anything.
overall tension change will be minimal; after all, 4 of the 5 strings will be the exact same size and tension, just moved over a slot.
Guitar Repair Gnome
Alpha Music, VA Beach