TL;DR -> IMHO, Resign and the board can appoint you as interim director.
This is an interesting parliamentary issue.
Article III: Section 1, excerpt wrote:If the number of Directors falls below seven, the remaining Directors shall elect replacement(s) within 30 days. The Board shall have the responsibility to appoint as quickly as practicable an interim director to fill vacancies caused by resignation, removal, or death.
There are two sections that mention interim director: the section above related to the power of the board to appoint in interim director in the case of resignation. And another:
Article III: Section 10, excerpt wrote:Elections may be called to elect a replacement Director for the remainder of the term of the Director removed if there is more than 12 months remaining. If less than 12 months, the Board may appoint an interim Director until the next election.
This section specifically differentiates between replacement director and interim director.
Article III: Section 2b, excerpt wrote:Each region shall have two Directors on the Board, and there shall be at least one at-large Director (having no regional affiliation)...Regional representatives shall be elected only by Chapters within their regions.
This section implies that the regional directors are voted in by Chapters' vote. By inference, if you are not voted in by Chapters, then you are not a regional representative. I think the first clause is unambiguous only if held by itself. The second clause "Regional representatives shall be elected only by Chapters within their regions.", makes the first clause ambiguous. That is, there is no way for the board to appoint a regional director, even though it is very clear in other parts of the bylaws that the board is directed to appoint interim directors.
While it may have been the intent to treat vacancies due to moves and vacancies due to resignations and in a similar manner (I honestly do not know), it does seem that they are not treated the same in these bylaws.
That said, Robert's Rules is invoked in the context of the conduct of meetings ("Robert's Rules of Order shall govern the conduct of business.") but not NECESSARILY in all other aspects as a parliamentary procedure. (this should actually be corrected through a formal update in the bylaws).
Not only if we assume that Robert's Rules is the parliamentary authority, but also according to common parliamentary law, past practice provides a precedent action unless that practice is prohibited in the bylaws or other governing documents. And as you mentioned, both the Board of Directors and the membership have the power to interpret the bylaws. But in this case the Board of Directors is empowered by the membership to conduct the business of the organization between assemblies. So, while the survey of members you are conducting here may be informative, I do not believe it is controlling (and, really, how can it be without a formal vote?).
I find the discussion of policy and bylaws very interesting in part because I am a member of (United States-based) National Association of Parliamentarians. (Or is it the other way around?

) This is the organization that publishes Robert's Rules of Order. The purpose of the NAP is to study, teach, promote and disseminate the philosophy and principles of parliamentary procedure.
As an aside, I think the interpretation of the bylaws should be independent of how great a job you are doing. And based on my direct experience, THANK YOU for doing such a great job for the AGA and go in the United States.