I'll try to keep this as short as possible while still including all the details.

My mom's childhood home was torn down, but she was called and knew ahead of time so she could go see it one more time. There was a fig tree in the yard that would be destroyed, so she took a cutting this past summer (about 3 months ago). Needless to say, the tree is very sentimental to her. She got it home and put it in a pot. It took off like crazy and has been very healthy. Because of wanting to plant it at the new house (move will be next year), it's been in the pot with plans to move it to a greenhouse during the winter.

Prepping the yard for the temporary greenhouse and checking on the tree, it was discovered that the tree had run a taproot several feet into the ground with the first 3-4 feet being close to the surface. My dad was able to dig most of it up, but the remainder of the root broke off. Now , there's a question about how to care for it.

Does it need a bigger pot before winter?
Is there anything that needs to be done to ensure it's health and smooth transition to the greenhouse?
Does it need any additional fertilizer or food?
What should they do to the root extending through the bottom of the pot?

Many thanks for your help!!!