I'm sure your tree will survive in that gap. However it's a little tight in there, how would you reach it if you need to pick the fruit? will it get enough sun?

You might try a modified espalier without a support system, just pruning to maintain a 'flat' shape.  Branches could be weighted down with a string and rock.  All that would allow more access to fruit and sun to ripen that fruit.  Consider pruning to the ground any branch that gets over a certain diameter to help keep things in control as well as limiting the total amount of branches.  A variety that is smaller in stature and not a fast grower might be the best choice.

I'm thinking that a fig would survive in that gap. The patio enclosure usually has firewood stacked up against the inner wall. But that begins in the fall so the fig would get sun from east through the glass enclosure for most of the year. Then it would get over head sun and some light from the west through the green house. I think I'll wait until I get a fig thats a few years old and then I'll put it out there. Maybe a hardy chicago or other variety that I come across that shows potential. I don't have a marsilles vs but that might be an option as well. I think I'd probably have to wedge a couple of straw bales in there to protect the fig in the winter but I'm excited to give it a try. I may try to put some figs in the raised bed in front of the GH as well and try the bending technique that CCC1 has described in his post. So many experiments, so little time!

Thanks,
Little John

I second Elizabeth's suggestion about choosing to espalier the tree.  Properly done, you could probably fit up to 3 trees in that gap.