It varies a lot by dealer and type of problem. We often hear stories here about repairs that took 3-4 weeks, or sometimes even more. Too often the RV just sits there without even work-in-progress. However, I would say one week is typical at the better places, and 2-3 weeks at the rest.
Warranty work generally doesn't pay as well as retail repairs, so some shops put it at the bottom of their priority list. Conversely, the squeaky wheel typically moves up the list. Other people come in with "emergencies", real or perceived, and get quicker attention. Parts availability can have a big impact as well. Most RV shops have a main supplier, or maybe two. and rely on them to source everything. If they run into a delay, they often do not have anybody to quickly chase down a part, so time drags on until somebody has spare time to look. For parts unique to the RV, they may order direct from the factory, who in turn back-orders to their supplier, resulting in longer delivery times. The shop could have ordered direct from the source in nearly all cases, but they don't take the time to figure out who it is and put through a purchase order.
In short, your experience is fairly typical. That doesn't make it acceptable, though, and you should get on their case.