Hi Mike. The run from Trail Ridge Rd (Fall River Pass or Poudre Lake) to the confluence with the main run is for the most part a low water class II/III meandering stream. There is a class IV+'ish gorge near the confluence, but the entrance and the exit drops contain bad wood. I think you'll find the section from Fall River Pass to takout A to be extremely scenic, full of wildlife, but also super boney. Very little whitewater and more boat abuse than you may care for, especially now with the recent cooler temperatures over these last couple days.
Obviously, takeout A requires you to hike your boat up Corral Creek. And takeout B requires you to hike up to Peterson Lake. Both of these takouts require Long Draw road to be open, which hopfeully will happen by this weekend.
But, to answer your question, the chance of enough water on the upper poudre section + the gate open is unlikely most years (including this one). And as far classifying the above section as 'fun', well that's not how I would describe it at all unless you're on shrooms (or something).
As for paddling from A to B, beware of the horizon lines and know where to get out before 'Cool World' - this rapid can sneak up on you. Everything else in this section is easy enough to spot from your boat (i.e. pool drop character with distinct horizon lines).