Yes, that is a good idea. Get a separate charger and always run the house from the isolated side. This will be more expensive as a good inverter/charger runs in the 1k-2k Euros area and you would need two (unless you find a suitable battery charger which is not very easy). I lived offgrid for nearly a decade and built myself three different solar systems. I started with a small all in one and found out that they are limiting when you want to expand since you usually cannot add more charge controllers and/or panels (which are the easiest way to expand a system). I ended up giving it away and building the others from separate systems. My biggest mistake was starting with 24 volts instead of 48 volts. It is cheaper but it gets a bit dangerous as you step up the power usage and there aren't many options for breakers and such.