Hey Monty, I have a suggestion. Why not just use Austria in addition to Denmark? It kills two birds with one stone: a surviving Greater Germany, Nazi or not, would likely still control that territory and it allows you to go from 1946 to 2020 with no problems. FRG would be unsatisfying as it ends in the beginning of the 1990's, right as the really fun stuff comes around.
I think most people who would be playing this would not really care about the fate of Austria or Denmark anyways, as far as playable ORBATS goes
The only other question I have is what sort of campaign locations would be generated by using one or both of those ORBATS? I think that's mostly hardcoded isn't it?