According to the manual, Octavia has an adblue preheater, so you should not worry too much about it. If it is sold in your climate then it should work in that climate, but best is to consult the dealership what are their advices and guidelines.
I would personally ask about safe filling levels. I don't know how much adblue can expand while being frozen, so one thing to keep in mind, that maybe keeping it's tank full might not be the best idea. Also driving until the low limit of adblue might be dangerous, as less adblue will potentially freeze faster.
One advice from me - if you are refilling inside a garage or on the floor that you can't easily clean, then use smaller bottles. I once purchased 10l canister, the funnel was terrible, canister was heavy and I spilled a lot in my parking spot in the garage. When it crystallized, it created very slippery and ugly surface.