Hi DRC and welcome.
When you say 2 nights, does this include 3 full days of paddling? What we do is to head out the Friday of a long weekend to put in on the forestry road.. Last year we paddled on Friday night less than an hour just to set up a camp away from the forestry road (and partiers). Saturday in a long paddle, followed by a short paddle day on Sunday and another good half day of paddling to get to Rocky on Monday. We will most likely be doing this trip again this year and bringing two kids who have not done river trips before. If you wish you can circumnavigate all the big sets of rapids quite easily without the need to portage. All sets of rapids have good run-outs should you tip.
If you needed to shorten the trip, you could put in at Saunders campground, you would miss some nice scenery but only a few good rapids, one of which is Saunders Ledge, a favourite swimming hole of Monster's.

From here you could do it in 2 days of paddling.
An even shorter trip would be to put in at Horburg which would either give you 2 short days of paddling, or it do this as a day trip.
Check out this Reach Report from Mark's Guide for Alberta Paddlers for more ino.
North Saskatchewan River: Nordegg to Rocky Mtn. House