The recent movie Take this Waltz with Michelle Williams and Seth Rogen is kind of a spiritual sequel I always tought.
In heaven everything is fine

I said the same thing to my wife after we'd just watched the DVD for about the 3rd time, and she pressed me to say how the story would go, and then I realised I really didn't know.
I suppose why I originally thought it was that question Laura posed during the goodbye scene "will we ever see each other again?"
"I don't know.probably not for many years"
"The children will be grown upI wonder if they will ever meet each other"
etc.
Lots of what ifs.
I sometimes wonder what would have become of them during the war.
Alec would certainly have become an army doctor. He might have come home, or served in South Africa.
Fred was probably too old to be called up for active service, but might have got some commissioned staff post, but if not, would certainly have been in the Home Guard.
Laura would have joined the WVS or whatever it was called, and served tea and sandwiches to the troops on Milford Junction station. She might have palled up with Myrtle! "I'm sure I don't know to what you are referring!".
Mary Norton's husband probably would be called up, serve the whole war abroad, and Mary would have serial affairs with dashing army officers, preferably army doctors
"Oh, Doctor Harveydon't you remember me? Mary Norton. We met all those years ago in the lobby of the Royalyou were lunching Laura."
"Laura?..oh.[embarassed laugh].ah yes, er, Laura.
.Look, do you fancy going to the pictures? You see I accidentally killed two patients this morning, and the sergeant-matron is awfully cross with me and I daren't go back"

I have always been intrigued by the idea that there ought to have been a sequel to this film, set many years later.
Perhaps there even was one that I am unaware of.

The last sentence of the OP puts it best.

Very well said!