Sure. And the only thing I dislike worse than Jon and Dany having a child, which I agree is going to happen but way too storybook after its been setup that she can't have kids, is the idea of her dying in childbirth. Star Wars did that and it was lame then too.
My guess is that Jon and Dany do have a child, but Jon isn't the one to see it. I write this because I can't see Jon happy in King's Landing (too much Ned in him) and I can't see him going the full Aragorn. I used to think he'd never marry Dany, but they are foreshadowing that way too much now. So I suspect you are right they have a child, but Jon dies not in the final battle with White Walkers but in the after battle with Cersei's forces ambushing the survivors of the war with the Dead. This leads to Jaime and Dany joining forces against Cersei.
Jon dying makes sense to me, because again I don't see him in King's Landing, plus he has seemed like he's been on borrowed time since his resurrection, anyway.
Daenerys will have a child who, like Jon, will not know his father. I suspect she will do away with bastard names, and set up a line of succession that includes a simplistic and arcane form of democracy. [blackout]Tyrion was hinting at something like that in "Beyond the Wall."[/blackout] Tyrion will have a hand in whatever that is.
Jaime and Brienne will have the "happy ending" of running off together. Bran will go be the Three-Eyed Raven Beyond the Wall, and Sansa will get to rule Winterfell. But it'll be bittersweet, because she gets what she wants but her family will be gone at this point. Bran leaves, Jon dies, and Arya... well I'm not sure what they'll do with Arya.
More or less my predictions.