DELLA 18,000 BTU 21 SEER Wifi Enabled Mini Split AC

We've ran a 21seer 18000btu Della, (an earlier version but the same as this mechanically) for 2 years now, and it cools our 900sqft cabin into a meat cooler & just love the thing for that! This winter we've decided to heat with it as it cost 1/5 the price of electric heat.We are just coming out of a 30hr period below 0, tipping at -6. I can say down to -3this mini split keeps heat, past -3 it felt a little chilly but it still did the job. The inside unit sounded like a sinking titanic for a few seconds every so often below -3, but that stopped once we came back up. VERY IMPRESSED! Very comfortable heat as well. Note*. Our minsplit is on the east side of the cabin, provided a very nice wind block.