Can I go ahead and dig it, or wait until spring? Thanks for helping with this. As you can tell I am very inexperienced with bonsai. It’s an after retirement endeavor to get me out of the house.
I just had to scroll all the way back to the start to try to find out where you live. It makes it so much easier if you add some more details, especially location to your profile so it is visible every time you post.
I guess it is early fall in Texas and winters will be mild. Coupled with privet resilience I would say that transplant now would be possible but no guarantees. Given that it is a large leaf privet and not really very interesting trunk it won't be a great loss if it does not make it but the process should be good learning experience.
You should be able to find a much better candidate for bonsai if you keep looking so don't get too precious about this first candidate.
Spring transplant generally gives more assurance so we will have to leave the decision to you.
Don't underestimate the work involved in transplant.
The hole required to extract any tree will be at least twice the size you imagined.
Trees seem to weigh around twice what you estimated before starting so work out a feasible way to get it out of the hole and to transport from collection to growing site.
I firmly believe that removing soil from around a trunk allows it to expand so when it is out the tree and roots will be much larger than you estimated so won't fit in any of the pots you had available.
Just letting you know before you start.........