Avocados and Frost in Europe (plus info on the cold-hardiest avocados and how to grow them)

Hi everyone!
I'm here in Paris. I ate an avocado fruit and I found it so tasty and creamy so I decided to plant the seed. Success, has a lot of leaves now. My only concern is, can I not disturb or hurt the roots as I just planted it in a small pot. And I want to transplant it in the garden.