Nice map and cool scenario! How exactly do you play a map game with yourself? I tried to do the same thing ages ago, but it never really worked out.
Don't know how @tungsterismapping does it but I do it all the time. What I do is find a base map and then edit it year by year while also saving all those maps. In the end it leads to a bunch of maps editted in Paint that are impossible to share on this site since there is about 30 of them in minimum. Not all but a lot of the maps I post are actually from solo map games. (Edit: I mostly simply post the latest one when I post from them, I have about 3 "solo map games" that are stopped because they are at 2020 and also another one at 2020 that I have been wanting to turn into a full timeline (probably a Graphics TL and not a writing focused one) sometime so I am working to give it some depth)