We sought counsel's opinion on the flying freehold issue, and they pointed out that we had the right to exercise CE over the (empty) unencumbered freehold property next door. Unfortunately we couldn't afford it (and didn't want it anyway).
Funnily enough that was what I was going to suggest. Might be workable if you can find a white knight investor, but it's still likely to be expensive and a PITA.
Yeah that's abnormal.
Also: what a ball ache