You ask what type of advice would best serve this situation. I would suggest asking a different question: What type of advice would best serve YOU in this situation. Seemingly only slightly different but takes you down an entirely different road. I understand where you are and what you seek. We all do. But it is very early in the game and what you should be seeking to reclaim at this point is yourself rather than the relationship.
Like many people I would assume you somewhat lost yourself in the relationship, especially during the end going through the separation and divorce. I know you have a goal of where you want to go but do you really know where you are now? Many people learn a lot about themselves during a divorce. Many people fall "asleep" during a relationship. Other than getting back with your ex what else do you want? Is there anything else?
I know that it is very difficult to think of anything but getting back together. Does it happen, yes, it happens. Does it happen with the state you are in now, rarely. Look at it like this - reconciliations do happen but healthy ones usually happen when both people have disconnected from the unhealthy previous relationship, have grown, and have been disconnected enough to honestly feel how it is to be alone and without their former partner.
Lastly, for now, you note how the two of you have no reason to stay connected in anyway in your daily life and are concerned as to how to keep some type of connection to keep the potential of getting back together real. My ex and I originally had a whole country between us and we ended up marrying each other when we previously lived 1000's of miles apart. We also ended up getting divorced when lived inches apart. Time, distance, space, lack of contact - none of these things can keep two people apart if there is a connection.
I hit on a number of points here - try to think about them and see if anything resonates with you.
