Yes, it’s possible but there are several sections (typical shortish Ruahine gorges) where packfloating will be required.
A good route out on a fine mild day but not advisable after rain. In that case there is the option to head out via Mckinnon Hut.
Yes it is good travel no pack floating is required. I have done different day trips from Kawhatau base over colenso south along mokia dropping down to crow. K base to mckinnon. K. base to crow. Purity to crow. All have been day trips and no problems. Times have been different depending how much i drank the night before.
Crow hut is in my back yard.