Just a update on this. My cert was expiring in early March and was extended already for 31 days I booked a property that ended up cancelling on me (The last room had already been secured directly with the property before Hilton's central database could update). The agent without asking offered to add an additional 31 days to the expiry. She actually fat fingered the day twice to the wrong date but quickly changed it; so it seems like a very easy process to extend any number of days they just have very strict policies with the 2 Weeks/31 Days.