We just returned from a long weekend in the area just south of Portland. It did look like you'd be waiting a while to plant in that location. Talk about supersaturated soil! It was nice to come home to much drier ground...
I did buy some tubers from a dahlia farm...I'll plant them in pots today.

I am in the NorthEast and it is going to rain for a week! It has already rained for a week! I want to amend my soil but it is much too heavy .

Last 2 weeks, our part of the Ozarks has had 15 inches of rain--with more today-and all week. My dahlias are in gallon nursery pots, so at least they can drain.

I live in the PNW too. I've been crossing my fingers that the week of May 14 will be a good planting weekend. I know that Puget Sound Dahlia Association plans to plant the Volunteer Park garden that weekend and I was planning to participate. I've been checking the 10 day weather report every evening. There is a warming trend, but it's coming on very slowly. I'm considering taking my car out of the garage just to make room for more pots! I have any nuber of tubers that are raring to go.
Phyllis