Sweet cherry grafts at the end of the season

sweet cherry grafts, at the end of the season. we'll have frost soon, all of this year's growth is hardening off. and next month all of these leaves will drop. some of these grafts put on three ft, a result from topping the pin cherry trees in late april while they were dormant. I'll collect scions in november since we really can't be sure the sweet cherry will survive the winter, so maybe 1/3 or 1/2 of the growth can come off - it will help the branches thicken and create laterals next year. I'm thinking about grafting onto pin cherry seedlings.