Nice garden . its a good thing when they out grow your area .
If you can hook up a big fan to exsahst area and great airflow it would help veep them small. (Lower temp plus airflow moving plants helps keep them small )
Might be able to recess potters in ground to pick up a few feet . or just strait up drop floor of green house down 2.5-3 ft (it would help keep root zone cool ) . that and some crazy training (towered center of hoop,house should pull it off )
Just some,out side,perspective .
What parallel are you at ?
Massachusetts.
Digging is allot of work. If I still had a bobcat it would be easy to pick up the sides and slide a few more timbers under there. That's not off the table yet, but it's not worth wrecking the house. The ones that get booted outside will be fine. They're weeds right.