If you loosen/remove the vent plug, your board should be fine tied in the rafters of your
In the attic, in your house would be better/warmer, but if the carport is the best option
you have, it should be OK.
Has it ever had any water inside?
If not everything should be OK.
If it's been wet, then outside storage, without drying out the core, would probably
not be a good idea.
Hope this helps,