One of my apple grafts is growing in well while the whole top of the root stock and backup graft are still dormant. would it be detrimental to cut at the red line now so energy doesn’t get wasted feeding the upper rootstock/backup graft when they wake up? Should I wait longer?

The rootstock had a tree fall on it over the summer snapping off its last scion and all it's leaves/branches, so it doesn't have a huge amount of energy stored in its roots over winter