What do you all think a typical FO to Captain upgrade time will be at a regional 5-10 years from now based upon current hiring predictions?

The way I see it, if I fly as an FO for a regional for a couple years after flight instructing, I'll have around 2,500-3,000 hours total, which I've always thought would be enough for a Mainline. (?) If I were to get an offer by a Mainline as a FO a couple years in, there really is no reason at all to stick around and wait for the Captain upgrade at the regional...