Lemons in zone 6????

Lemons in zone 6????

I was at a park today (Harkness State Park on the shoreline in Connecticut) and I saw what looked like a lemon tree (shrub?). The leaves looked a little smaller than those on my Meyer lemon, and the fruit were also smaller, the size of golf balls. The fruit were also a little on the fuzzy side and not quite yellow, a lttle on the green side. There were LOTS of thorns. Is it possible a lemon could survive up here? it was a sizeable plant, I don't see how it could be dug up and moved indoors. any ideas? sorry no photos, I didn't have my camera handy :(
My Messy Room

My Messy Room

Drapes

Drapes

The Community Garden (allotment)

The Community Garden (allotment)

First bloom of the year :)

First bloom of the year :)

My room.

My room.

my apartment

my apartment