There are several plants that go by the common name of 'bearberry', so it would help if you could provide the botanical name. If you are referring to Arctostaphylos uva-ursi, it is native to much of the upper half of the US so should be relatively easy to grow anywhere in that range. It is extremely cold tolerant (zone 2) and only needs a lean but fast draining, acidic soil and a reasonable amount of sun. It tolerates a fair amount of shade but does not grow as fast or as dense in too much shade. Requires no irrigation once established and no fertilizer.

It is a hugely popular groundcover in my area.

Yes, that’s the bearberry in question.

I bought many small Arctostaphylos uva-ursi plants last spring and had one die over the summer, probably due to heat and drought.

We had an unusually cold couple weeks this winter, and although my own plants were apparently sheltered enough to be undamaged, I noticed several mature plants in the neighbourhood with dead brown foliage in the spring - they are green and looking good now.

It seems to be very sensitive to any disruptions which seems like high maintenance in my case.

What kind of disruptions? It doesn't take to transplanting very well but then I'd consider that activity to be high maintenance in and of itself :-) Otherwise, provided the site is appropriate, you just stick it in the ground and let it go.....doesn't get much lower maintenance than that!

Except it is quite susceptible to leaf spot in our area, with even native colonies in the wild often having it. In fact much of the point of the 'Massachusetts' cultivar is leaf spot resistance.

https://pnwhandbooks.org/plantdisease/host-disease/kinnikinnick-arctostaphylos-uva-ursi-leaf-spot

Yeah, no transplant tolerant like other plants I have. I think Ken would say toss it if is problematic :)

For many years I had a magnificent bearberry--some 20 feet across, though it never bore fruit (obviously needed pollinization). Then two winters ago, in February, we had extremely warm weather (mid 70s) for two weeks. Then it got cold again. Most of the bearberry died and it really has never recovered, thought I cut out all the dead wood. It was a real heart breaker. I still haven't reworked the spot.

I have or had one plant. What do I need to get berries?

A healthy plant in as much sun as possible. And the presence of early insect pollinators. The flowers are perfect and the plant self-fertile so cross pollination is not a requirement.

HERE is my previous thread on this topic. In eastern US, if you can imitate the conditions found in the wild you may have a chance. I describe these conditions in my thread about colonies found in the NJ Pine Barrens.

Interesting related link, thank you!

My bearberry never bore fruit in the nearly 20 years I had it though it flowered profusely. And I have lots and lots of very early pollinators.