First, I am not sure what happened with [Wikimedia Cascadia], but there were a number of emails that were delayed until this evening including yours. Forgive us therefore for not responding to you sooner.
Second, others will need to weigh in, but in MHO, I think that the best means would be to have someone come to us _and_ sessions at WikiConf. I think that between edit-a-thons that have been held in Portland, OR, interest in doing edit-a-thons in the Seattle area, & professors at University of Washington who have had students edit Wikipedia as part of the class, I think that there would be more effective to have you come from DC than to have a few of us come from Seattle.
Third, I think that having sessions at WikiConf USA is an excellent idea that would benefit us nationally. From what I hear, it is likely that 2015's WikiConf USA may well be a follow-on to Wiki Education Foundation's efforts. If this is true, I think that training in best practices of workshop facilitation would be a natural fit.