Life does not stop with a cancer diagnosis. It should not. If you have cancer, you are still a person. You do not need to let cancer take over everything. You are still a human being and need to do normal human being things. Like going on vacation. Or moving to another state.
If you want to go on a vacation, all you need to do is talk to your oncologist and they will help you figure out what changes need to be made. If you are in the middle of chemo, you can probably take a week off. Its not that complicated.
Your cancer diagnosis does not get to swallow you whole and take over everything in your life. People in cancer treatment also do things like visit friends, go shopping, go to the movies, and all sorts of other normal every day things.
The emotional break you get on vacation while you are dealing with cancer can be very beneficial. It can be very nice to just get away and not think about infusions, surgery, oncologists, tumors, and all sorts of fun stuff. (But if its related to cancer it is all crap.)
So go plan that vacation and have fun. You may not be up to sky diving but you can still go to the beach or admire a beautiful view.