I had grafts last year wake up around mid June last year. Was loosing hope for a winter wildlife I grafted. It woke up a month after most of my grafts did, around memorial day. I planted them in pots and let them sit in the mid 50's degree basement for 3 weeks to heal. Then they were on my covered east facing front porch for about 2 weeks.
Best graft takes have been my crossbow. I literally pruned them fresh off the vine. Lefts 2 or 3 lower limbs to use as grafts. At most, those grafts had 3 hours off a tree. Not sure it mattered, but left the east side lower limbs as scion donors. The garage shades the east side by about 2 hours of morning light on the lower part od the tree. Maybe the garage is 25 feet away.