Ceremony backup location

Happy New Year all. I am in need of a word Smith. I am getting married in Wisconsin on May 2 on family land outside. Due to the unpredictable weather in Wisconsin in early May, I have a backup location(still family land but "inside"). We honestly wont know until the day or 2 prior which location we will hold the ceremony. We are going to set up a voicemail that says which spot to go. #1 or #2. How would one word this on the details card? My invitation says location #1.

Thank you in advance for any help provided.