Depends on what your banking windows are. If you are within the last two months of your use year, you might not be able to do anything with them, and they would be lost. If you are well within your use year, you will be able to rebook if available, and if needed, bank.
OOPS, I just noticed the 7 days thing. Any time you cancel a reservation less than 31 days out, the points go into holding status, and can only be used to book reservations within 30 days of the trip. They also have to still be used in that current use year, so you would have that deadline as well.