Corey-Boy, I hear you! I am a fair-weather gal, myself!! I don't like riding in the winter, even though I live in Canada! I used to ride in an indoor arena that wasn't heated, so when we rode hard on chilly winter nights, our horses' sweat would fall back down on us as snow! Gross! Anyways, a 40m x 20m arena would be just fine for you :) best of luck