sounds like you have a great practice regimen down. When I was prepping for a baited bear hunt, I did a lot of shooting seated offhand (even in a tree stand in the yard) and that makes a big difference. it will feel like clockwork.
I hope you get a crack at that big wise ol 7 footer! I am sure you will have fun either way
"If you are going to go through all the trouble to put a hole in something, why not make it a big one?"