I just finished a 1968 ranch retrofit in Minneapolis: a 2‑ton cold‑climate heat pump (Mitsubishi H2i) paired with a 7.2 kW rooftop PV array, and we eliminated winter gas use while holding 70°F indoors during a −10°F cold snap. If you’ve done similar, how are you sizing for shoulder seasons and handling hot water — standalone heat pump water heater or an integrated system?