score:9
It seems (from United Airlines' website) that you may cancel your current reservation and make changes to it for the next year from the date of issue
Can I cancel my reservation on united.com?
Yes, if your plans change and you prefer not to change your itinerary immediately, you may cancel the reservation and return to it later to make flight changes for up to one year from the date of issue. A change fee may apply.
This may be the perfect solution to your situation.