Jonathan
I think to max out long distance flights you need a couple of aspects; One is the ability to get away early in the day and two, landable terrain downwind in case you bomb out say 10-70 miles from your departure airport.
I don't think Marfa has these quality's, but I'm not sure.
A couple of days ago I was looking at a USA wind chart and there was a fetch of wind straight north to Canada from the Odessa area. It was very even and straight.
I'm interested in doing this and may try to get a meet together in 2021.
I think this time of year might be prime, There's still cold fronts sweeping down to create long south to north prefrontal days and the days are starting to get longer. Need to do more research thou on a optimum starting airport and best likely time of year for good downwind conditions. Kinda like a Dust Devil dash but in the middle of the USA.
Have a OLC camp too for something to do while waiting "For the Day"
I'd like some of the Texas crew chime in on this idea.
Nick
T