You aren't saying you are going to Memphis to pull your sub window, I hope.
You keep the deviation bank no matter what. You can use that ticket money for whatever you need, that month. Get to Memphis however you like, but you sure don't need to show up in Memphis if you're just in sub status. I personally just hope they don't assign me a sub trip, but if they do, I then make my choice whether to keep the trip or not.