Actually, yes! I have a goji berry.
Everybody says they are easy to grow because the roots are so invasive and spreading, but in a container I find them challenging. Overwintering them is not easy without a greenhouse. I barely managed to keep mine alive after the first winter. The year before I had to start over from seed when it dried up indoors.
I've had mine for several years (2 of them) but they haven't bore fruit. I think it's because they're on the shady side of my garden. They survive the winters fine though (I'm in zone 5). I've started some new seeds from some berries in the trail mix that I like. I will plant these on the sunny side.
Zone 5 gets well below freezing in Winter.
May I ask, have you always left yours outdoors all year in winters? If they lose all their leaves after frost, do they always kick back in Spring?