Ok, for me , teaching is rarely more than 2-3 hours, although there are block courses where i have to be with the students all day long for a week, but i do not have to talk all the time then.
The important thing to me is that eventually after 6 months or 12 it will all be good again. Sadly few have that experience yet to say if the voice is as strong, loud, powerful as before, is one gets strained more or rather less, if shouting is ok... Most here are jus some weeks post op