30F is hardly anything. Mitsubishis can work down to -13F/-25C and still have a COP of 2.08: * https://www.mitsubishicomfort.com/articles/keep-warm-this-winte

30F is hardly anything. Mitsubishis can work down to -13F/-25C and still have a COP of 2.08: * https://www.mitsubishicomfort.com/articles/keep-warm-this-winter-inverter-technology-for-any-climate https://www.mitsubishicomfort.com/articles/keep-warm-this-wi... * https://mylinkdrive.com/viewPdf?srcUrl=http://enter.mehvac.com.s3.amazonaws.com/DAMRoot/Original/10006%5CM_SUBMITTAL_MSZ-FS12NA_MUZ-FS12NA_en.pdf https://mylinkdrive.com/viewPdf?srcUrl=http://enter.mehvac.c... Heat pumps that look like standard ACs often can run at 100% capacity down to 5F and still have a COP>2 (1=resistive heating). Also worth perhaps looking into how leaky your house is: * https://www.energy.gov/energysaver/blower-door-tests https://www.energy.gov/energysaver/blower-door-tests and then after that maybe insulation.