Justin.....just fire it up you sally. You just dropped a couple on Lake Creek (albeit low)....but impressive. You'll be fine up there bro, and wish I could join you guys but I'll be heading north to Idaho. Not sure what the rock will say this weekend and I haven't paid attention to the reports, but if it gets above 3.5, narrows gets pushy (upper especially). Middle is short but kick ass. All very easily scoutable and safetied.
I'd do it this way for a Poudre virgin (of your paddling skillz). Hit Middle Narrows and see how it feels as a warm up, you put in just below the "White line" and run 1.5 miles or so....pretty continuous. You'll take out at the bridge that is the entrance to Lower. Take a look at it and see what you think. I'm sure by then you'll be salivatin'......fire it up. Head up to the Upper and check your pants for big balls (if it's high).
Keep in mind that a swim in Upper or Lower and potentially Middle is NOT going to be pleasant......and probably long.
Bridges take out is a good place to hook up with some guys that know the lines a little better. Also, if you hang out at the Narrows long enough, paddlers will come. It's not a bad idea to talk to and/or watch a couple guys through those sections, there can be some tricky spots.
I'm planning on heading back up there around June 14th/15th.....