Unless you're really cranking in old-school kayaks, Pumphouse to Dotsero is going to be more than a couple of days, especially with the flow dropping. You may want to plan on at least 4 or 5 days for the entire 60-mile trip...
There should be parking at the bridge at Dotsero, which will be a good place to take out.
Have a good trip,
Nothing in the world is more yielding and gentle than water. Yet it has no equal for conquering the resistant and tough. The flexible can overcome the unbending; the soft can overcome the hard. - Lao Tse