Paint should be just fine in a year or 2, especially an unopened can. Unopened activator should be fine. Opened activator probably won't be. There is inert gas, Bloxygen I think a brand is, you can shoot into a can before closing, but personally never tried it yet.
Meant to add to this that opened activator cans at the screwthread area should be wiped with a rag both inside and outside especially before even a days storage to avoid white specs getting in your paint from dried activator.