The next major plot development would be Elly becoming pregnant with his child. We could compare notes about what a basket-case John was with Tom being less inclined to whine about how awkward he felt while ignoring Elly's confusion and discomfort. We could also have avoided the desperation-measure name of April with the more modern-sounding Robyn because the only voice running his or her mouth about tradition would be shouted down by her husband. (Marian, there are people dying in the streets and you're worried about trendy names? Get a life!)
Speaking of Marian, her and Farley's deaths would still be the boundary posts between the Middle and Later Years. Instead of the treacle we had about sunshine and shadows on the one hand and the cut scene from Apaches on the other, we'd have had Elly finally getting some sort of closure on the one hand and the last time John would be an important factor on the other. This is because in the first instance, Elly's taking care of someone who seemed terrified of her happiness might finally get the old bat to see what she did wrong and in the second, trying to figure out how to make an old dog's last days comfortable might finally get a train-obsessed man-child to see what he threw away.