Most of Horizon's Q400 flights are short, around one hour on average. In my "best" year at Horizon, I logged 840 hours. The typical number is more like 650 - 750 hours per year. I once flew an eight-leg day that blocked out at 5.3 hours.
From what I've heard, the Q400 upgrade time has now dropped to 1.7 years. Incredible! Including training time, this is just about the minimum amount of time for one of our pilots to get to 1000 hours of Part 121 time. Of course, some of our pilots have worked at other airlines, so they already have some Part 121 experience.
As Snacky has pointed out, get ready for a captain shortage!