All relative to what you're used to sailing in and your crews experience. Having not been out in two months we know you'll be on your toes as opposed to the midseason case of the careless or shall we say **** capsize.
I know when you haven't been out in a while, it seems or looks windier while on the beach setting up than it actually is when you get out there and the juice is flowing.
Around here if the grass in front yard is moving we start thinking about going to the lake. What's too windy? You're the best judge of that.