Perhaps having teams declare what District they will participate in at registration would make this work. You automatically have to attend 1 District event for whichever District you select and should you qualify at the end of the season that would be the District Championship you would attend. 2nd (and 3rd and 4th) District events could be in any District and you would accumulate points there via whatever point sharing system is decided on. As an example suppose you have two teams in Iowa, one in the northern part of the state and one in the southern. One declares as part of the Wisconsin/Minnesota (WM) District while the other is part of the Iowa/Nebraska/Kansas/Missouri (INKM) District. Both can attend the Minneapolis (WM) and Kansas City (INKM) District events (the 2 closest events to both teams) but the northern team can attend the WM championship in Minneapolis while the southern team can attend the INKM championship in St. Louis, which are the respectively closer District Championships for both teams.
This also allows for teams in far flung places that aren’t likely to ever have more than 1 event (Hawaii, Alaska, Puerto Rico) to always attend their local event regardless of what District they decide on that year.
I’m in favor of letting teams declare their own District, then they can change Districts if new events are created closer by or the District Championship moves. For the far flung teams they can travel and see a bit of the country this way too 
I think there has to be a requirement that a team attend 1 District event within a District to be eligible for that District’s Championship. Otherwise there is the possibility of teams gaming the system by attending weaker events in one District (say MAR) to gain eligibility for another District’s Championship (say FiM) without ever having to compete against the teams from that District prior to the Championship. Since every District Championship should be in a population center that will have a District event as well it’s unlikely that a team would have a District Championship close to them but have 2 District events closer to them from a different District.
