Growing a small grape "tree" is called head trained or goblet in the vineyard. It works best in hot dry conditions but I plan on trying it in VA. There are vineyards that do it in CA and Europe to this day. I recently saw
some when visiting Croatia but these were not trained up to 4 feet, rather they were only a foot off the ground at best.
There is a grape in Umbria Italy called Sagrantino that for a long time was forgotten. Only a few small vineyards had it and one of them used to run the vine between fruit trees in effect using the trees as the trellis.
The vine has become very popular and I think they have taken those down in order to plant more using a traditional trellis.
So yes vines can be grown this way. If you are in a humid climate and not too far north ( i think MD might be the cut off for muscadines) I imagine head training a Muscadine could work well but I have not seen a Muscadine trained in this way yet.
