To me, the current supply sounds more than adequate. Details matter,
though.

It makes a huge difference how many people live in the house. Is it
3000 square feet and 2 people, or 3000 square feet and 20 people?
Do you expect to run the A/C at full blast and the sauna at the same
time? Look at your monthly electric bills for usage, then consider
what units are consuming the electricity, and on what schedule. Do
you have consistent periods of peak demand? Are those peaks big or
small? In other words, is your usage spread over the day or bursty?

Una