This looks really cool, am looking forward to see more from you guys!
And you should check out the “Orbit - Weather and Seasons” pack from the marketplace. It’s super cheap and will give you a full, customizable day & night system + weather effects (even storms). I bought it a while ago for my own project and am really happy with it.
The link is here: Orbit Weather and Seasons in Blueprints - UE Marketplace