i want a heater!!!

sick of waiting for just solar to heat pool in spring. thinking of heat pump. not opposed to propane...but how much trouble and expense will it be to tap into existing propane tank....about 120 feet from pool? i thought a heat pump might supplement solar heat nicely. any chance of year 'round swimming here in northeastern nc? if so, what winter precautions do i need to take since the pool will be open all winter? i really want a sunroom with a swim spa, but that's a few hundred thousand dollars out of reach. any ideas or suggestions appreciated.