For me, the most important lesson was this. Without a separate heating source, and if you're in a climate where temps drop below freezing for multiple days, you are not going to be able to sustain the same level of comfort with solar alone. I mean you can, but the cost of panels and batteries and the associated support for those is going to be hard to justify for simply covering needs for a few days a year. If you're in a cold climate you probably already have a different heat source. If you're in a more temperate climate you may want to consider one. This should be especially important to newbies, reinforcing that you should be realistic in expectations and plan accordingly. Even with lowered thermostats and other reductions in use you may run out of battery fairly quickly. Of course, there are many factors and my example is likely not typical so there's that. Heating a 1200 sq ft home with good insulation, high effieciency heat pumps, and proper management would be much more doable.