You are right, the shortest possible size of a pram is not really put p on websites at all, which is why even I won't be telling you the exact measurements, I don't have these at home at the moment :-) But logic can be used here a lot, meaning you need to search for a stroller that the handle telescopes in as much as possible, OR rotates totally (that is not the case of many strollers, but for example a Britax Go Big 2 offers that option and would be my first recommendation).
The Bugaboo Fox is another nice option as there, the handlebar telescopes in totally (and the base in which it goes is low-ish), and it is not a huge stroller overall. So that should work for you.
With the Priam, I cannot say I am sure with the overall length, BUT it does offer the two-wheel mode (just like the Fox does) so you should be able to put it up on two wheels if necessary. However, the wheels, mainly the front ones, are not as awesome on terrain and the handle tends to rattle a bit, so if you're searching for a more all-terrain model for bumps etc., I would actually not pick the Priam I believe.
The Joolz Day Plus is a bit robust overall while also having front wheels that are not as much all-terrain as I would wish for that size, but the push is nice, still... But I wouldn't go for that one either, I think. Unsure about the size.
I also think that Jané strollers with the telescoping handlebar (actually probably even those with a swivel one) would also all work, size-wise.