>The new USDA chart that came out a couple of years back said that we were now zone 6, but then the winters instantly got worse, so I still go by zone 5, and if possible get plants that will take zone 4.<
They moved us to the warmest subsection (A or B; forget which) of Zone 5, from the warmest of Zone 4. Seems to work for friends 500’ lower, and on a western exposure; but not for us. We still get Zone 4 stuff, and lose some of ‘iffy’ 4 items; try to get Zone 3 for anything on the expensive side, just to make certain.
Have to really check plants out, too, via Google before ordering.. Not all the sources always use the same designation. Sometimes, it’s because some are using the new Zone info; other times it depends on the specific cultivar, which may be less hardy than the generic species, but they list the species zoning.
Yes, we are more careful now, after several zone 5 failures the first couple of years.