Dear Ice Cream Van:
Have you looked outside recently? We are most certainly not Walking in a Winter Wonderland right now. And I'd really rather not be for a few more months.
And while I really do appreciate your wishes regarding my Christmas experience, need I remind you (again) that similar wishes for the New Year could not be any less timely and approriate than they are right now?
Consider this your official warning. If I have to write again, I may just have to make it a break up letter.
P. ost S. cript
How about you try something like these on for size?