Card for Greek Teacher

Γεια σας!

I'm just finishing up Greek 101 with an amazing Greek professor, and I'd like to write a few words of thanks inside a thank-you card. Since it was my first semester of Greek, my vocabulary and grammar are still quite limited.

In English, what I'd like to say is, "Dear [Name], Thank you very much for the wonderful semester. Have a great winter break. See you next year!"

My best attempt at translation is, "Αγαπητή [Name], Σε ευχαριστώ πολύ για το υπέροχο εξάμηνο. Καλές χειμερινές διακοπές. Τα λέμε του χρόνου!"

I'd appreciate any comments/edits to ensure this sounds natural and avoids errors.

Ευχαριστώ πολύ!