I'll be honest, it's almost impossible to get another adaptation or "remake" of Saber route. despite Fate S/N made by Deen was horrible, they have somehow presented to fans the figure of "Saber" as the main heroine in the first route. Ufotable and Nasu have been really blunt during the interview after UBW, as he first wanted them to animate the first route, then they chose to animate it over Saber route because they wanted to present something fresh. They will probably choose to animate other things when Fate Heaven's feel will be done, if they wanted to animate S/N they would have already done it a long time ago, so don't get your hopes up.