Geez, you have to bid to cover someone's vacation week there? Only 2 cover drivers can run my route. If they were to both book off on a day I was out a sup would have to run it (poorly) with a random cover guy.
When I was a cover guy (and I've toyed with the idea of giving up my route and going back to being a cover/swing guy in a nicer area/center) I was regularly on a route for at least a week at a time. I knew about 8-10 routes and most of them were high seniority guys who had a lot of weeks. One guy took 6 weeks in January/February each year so I was basically on his route for most of the winter. One route I was on everyday for 6 months because the guy was out on comp. With the most recent contract, a cover of that length would have to be bid among the cover guys.
When there was a week where none of the routes I knew were open for the whole week, they'd usually call a guy with about 12 years in who they knew would take dead days and I'd do the route for 3 days of the week and he'd come in for 2. This happened so many times the businesses started calling it my route.