My original hive did not survive the winter

Sad to report that this hive did not survive the winter. It’s my first hive and I made some rookie mistakes with it. I originally ordered a NUC but with the delays last year, I opted for a package of Italian bees instead. I used the included foundationless frames that I had. Not long after the queen was released from her cage, she went missing. The bees reared up another queen but never recovered from that population hit. Local hornets bullied them. Despite all this, I was still able to harvest a few jars of honey in the fall. After this colony’s collapse I was able to get another 10 jars of honey, so they didn’t starve. The hive was treated for varroa in the fall and wrapped in the winter. My guess is that the hive numbers were too few to keep is adequately warm in sub-zero temps.