How long would you tolerate not having a fellow staff member, upon whose work you depend, away from their position? 8 weeks seems like a long time to have some

How long would you tolerate not having a fellow staff member, upon whose work you depend, away from their position? 8 weeks seems like a long time to have someone away from work, or to have to cover someone elses job during their absence. A lot of things can go wrong when people are gone from their work environment in that situation. From that perspective, it seems more than reasonable.