I have just been informed that the oven will not be available to me on Tday! How far ahead can I make my apple pies?

You could make and freeze the whole pie, unbaked, today or tomorrow (Wednesday). Defrost and bake it on Thursday before you leave your home. You could also bake it tomorrow (Wednesday) and, after it's all completely cooled off, wrap in plastic wrap and foil for travel on Thursday. If they have oven room at your host's home while you're eating turkey on Thursday, remove all the wrapping and let the pie heat through at 300 F for about 30 minutes.

You could make the apple pie on Wed. Do it, if you can after noon.