A lot will depend on what kind of refrigerator you have. A residential or 12v refrigerator will require significantly more wattage than an LPG/120V refrigerator that you can run on LPG while boondocking. And be aware that, unless you go with a huge installation, you won't be able to run your A/C off solar. The same goes for induction cooktops but you can always cook outside on a camp stove while boondocking. The gauge of your pre-installed solar wiring can be a limiting factor in how many watts of solar it will support, although running new wiring isn't that difficult. Whether or not you have a generator and your tolerance for how long you're willing to run it is also a factor. We prefer to run ours only to use the microwave and such but not to re-charge our batteries unless it's absolutely necessary. Others are perfectly happy to run their's several hours a day.
Additionally, your personal "power lifestyle" is a factor. As former sailboaters, we're conservative in our use but a family with kids who play video games and watch TV all day off an inverter is going to use much more power.
If your wiring and solar controller are sized for it, you can always add panels should your initial install prove to be inadequate.
I suggest you read all you can on solar, both on Winnieowners.com and IRV2.com to educate yourself. In a couple of weeks you'll have a pretty good knowledge base.
2002 Itasca Suncruiser 35U