I don't know much about the Kootenai, but have floated the NF once. I believe polebridge to Blankenship is a long haul for two days at this time of year. Polebridge to glacier rim, might be more of an overnighter with time to fish... but then again you said a couple of days, maybe that means three... I love the NF and that would be easy an easy decision for me, that and odds of a huge rainbow on the Kootenai are still pretty slim. I've heard that is somewhat of a unique fishery with specific methods so it may take some time to learn the how's and where's.
Yesterday's gone on down the river and you can't get it back. - Agustus McCrae