to be honest, Jonsa will never happen. seriously, they won't. cause 1) they see each other as siblings ONLY and 2) they are related. more related than Jonaerys. but that's not the only reason. Jon and Sansa GREW UP as siblings and then marrying each other would be much worse cause they SEE each other as brother and sister. nope, no way Jonsa is happening. don't get me wrong i like them as siblings and i ship family Stark as a family but nothing more and Jonsa would be just...ew now. Jonaerys is the real deal and everyone knows this. and those Jonsa theories make me actually laugh
all i wanna say is. we don't need to worry about Jonsa at all. i more worry about Jon and Dany surviving. i know they will make it to the end, i just don't want one of them to die in the series finale. that is my bigger fear than Jon and Sansa suddenly developing feelings out of nowhere.