What happened to the original poster?
There are a lot of different factors.
If you are "grid attached", you can build your system as big as your are comfortable with. And, you only need to be concerned with average power usage.
If you are "off grid", then you need to be concerned with peak power usage (leveled out some by batteries). However, if your power source is seasonal, it can be a problem, such as solar in the winter.
Another concern of "off grid" is how you are dealing with things like electric vs gas stoves.
Start with getting low power light bulbs. make sure you turn off lights when you're not using them. Shut off appliances when not in use. And monitor your actual usage for a few months.