@barguy8194
You are the White Mountains of New Hampshire, USDA zone 4, this is a short summer growing season. If you have less than 100 days between last frost of Spring and first frost of Autumn, I would NOT decandle the Virginia Pine as one would a JBP or JRP. Both
@Adair M &
@Brian Van Fleet who recommended decandling, live in much milder climates, zone 7 or zone 8, with nice long summers over 150 day long growing seasons. I think Brian is over 200 day growing season. Decandling only works in long summer climates, such as Japan, Memphis & Atlanta. I would recommend treating your Virginia pine as you would a Pinus sylvestris, Scots pine, or mugo, or Jack pine. The Virginia pine is technically in the same subgroup as Pinus banksiana, Jack pine, and Pinus contorta, the Lodgepole pines & Shore Pines. If you already have experience with either of its relative, they should be your guide. I treat my Jack pines more or less the same as I treat Mugo pines. Basically, everything is done after the summer solstice, most pruning and repotting and wiring is done in August (or at least that is when I do my work). For personal reasons, August is when I have time, and is when I repot. I have cool summers, with an average of fewer than 10 day over 90 F (+32 C), which is a relatively cool summer. I would assume in the White Mountains, your summers are similar.
I do find P. banksiana will back bud on older wood to some degree, best backbudding is on wood less than 10 years old, but I have had random buds sprout on older wood. Not real reliable, but it does happen. I would assume P. virginiana is similar.
I don't know if they are found near you, but P. banksiana seems a decent pine for bonsai once you get past collection & that first potting up from wild collection. They are difficult to collect successfully. Not impossible, but nobody has a 90% or better success rate for collecting them. 25% to 50% success seems to be "good success rate" with Jack pines. But if you have them near you, they have exceptional winter hardiness. They withstand incredible cold & exposed settings. I don't even take mine off the bonsai bench for the winter. They do fine exposed to all the elements. From seed and seedlings, they seem pretty similar to the growth rates of P. sylvestris and other pines.