If the “city” outside from which Jesus suffered is just the “city” that is meant as allegory for “here” (in the verse 14, meaning the “Planet Earth”) in opposition to the “enduring city” reserved for the Christians in the afterlife (i.e., the celestial Jerusalem in the higher heavens), then Jesus's sufferings have to be localized precisely “outside the city” allegorizing “here”, i.e. outside this world: in the lower heavens.
This interpretation is given by Couchoud and reported by Marc Stéphane (La passion de Jésus, fait d'histoire ou objet de croyance, 1959, p. 310).
Note that Richard Carrier wrote in OHJ that ''outside the city'' is to be meant as ''outside the celestial city'', but this is not precisely what the text says, since the city that is meant is the earthly world. Not the earthly Jerusalem and not even the celestial Jerusalem. But “here”.