Hey, OP, you know what you want, you've measured the space you have and listed your mandatory requirements. Far be it from me to waste your time by suggesting a Plan B. For anyone else in a not-too-dissimilar situation:
https://usa.dahon.com/collections/bi...hon-k-feather?
(In that great Dahon tradition, the specifications listed are absurd and contradictory. Sigh.)