Mine locks out at 32F and the burner has run a few times this season already. The sensor is too close to ground and tends to read low, perhaps it's time to drop the temp to 25F.
I wish we could get natural gas here! Of course where things are going it too, could be heading very high.
Next system will probably be a combination of geothermal and minisplit as I know many in the trade and can get deals that would make ROI shorter.