<p>Keshet Eilon, in Israel, is violins only and the deadline is March 15. It is directed by Shlomo Mintz and has exceptional faculty. It is not free.
Summit Music Festival in Westchester County, NY has a late deadline. It is not free and I don’t think it is terribly hard to get into. It has some excellent faculty including Aaron Rosand (he costs extra).
Many of the free programs are orchestra or chamber music based and are highly competitive!</p>