Good question...a couple nested systems. Noting that the house was designed to be 'a passive house' (air quotes) in the early 1980s so it has some quirks.
1) we have a large stove so needed a makeup air fan anyways to match the hood. I worked with them to design the makeup system so it is quiet and pressurizes the second floor 'landing' and is larger than necessary...rather than just immediately pumping air into the exhaust.
2) We also have high ceilings because of the shape of the house (it...should help?)
3) the high ceilings also have remote openable skylights (originally they had hand openable crank skylights) that are already really affected at releasing any heat buildup
4) an excess of windows and two multi-panel sliding doors which, because we are only heating and cooling rooms when they are occupied, can be kept open more frequently. All of them are under deep overhangs and 75% of them are south facing so they are great at managing solar heat gain and we can open them often.
I'm curious how it will work and we have some backup plans. We're putting CO2 monitors in the bedrooms and the kitchen when we move back in and if needed a bunch of the systems can be connected to home automation rules if needed. Even the exhaust fans for all the bathrooms are on the home automation system already.
We lived in the house for about a year before rennovating it with 2 mini splits retrofitted (long story). It's 1900 square feet and we both worked from home. At night, we heated the bedroom, during the day we heated the office. During winter the sun heated the rest of the house. Our total power bill was around $70 a month.