Hi,
With a small bank it is important to get back to 100% from 50%. With a larger bank you may only be getting from 75% to 100%. That means the ratio of watts of solar to amp-hour capacity can become lower. If the bank is sufficiently large, then 60 watts per 100 amp-hours may replace all the energy used per day.
If a large inverter is used lots then solar wattage needs to bump up again, to replace the energy so used. If my plans go as I hope, next year I'll be running the air conditioner from solar, so I'll need about 1250 watts of solar.