Meiningen only has Friedrich Constantin at 37 still unmarried.
Andreas of Coburg has two sons and one grandson. His daughter-in-law is 43 so unlikely to have more children and his younger son unmarried at 41.
Saxony itself had to go to the Gesaphe branch through a female line. Previous Message
It is an anomaly among the German princes that the Ernestine branch of the House of Wettin has never fully adopted primogeniture. Instead the branch has allowed several princes to share sovereignty at the same time. Over the years the geographical divisions have varied tremendously. Nobody, I think, regrets that today we do not have dukes of Saxe-Coburg-Eisenach, Saxe-Coburg-Saalfeld, Saxe-Eisenberg, Saxe-Hildburghausen, Saxe-Jena, Saxe-Marksuhl, or Saxe-Romhild. The divisions of land between the princes of the Ernestine branch have always been temporary. There is no reason why the divisions which existed in 1918 must be maintained forever. In fact, it is likely that in the future there will only be one Hauschef for the entire Ernestine branch. I can't see that this is problematic in any way.
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Noel S. McFerran