First off, thanks for your flexibility and for figuring out a new date with the Host.
As long as you've put in a booking request (even if it expired or was declined/cancelled), the property is still under your claim. You can request a new date at any time and the Host will be alerted—so once you make another booking, you'll be all set.
If you need to reschedule an assignment that's confirmed but the assignment date has passed, you’ll need to reach out to support@hipcamp.com for help rescheduling.