Your tires didn't drop 7 psi merely due to temperature changes. The gas laws sow that the change would be 1.8% (percent, not psi) for each 10 degrees (F.) of temp change. The 24 degree drop would change your 80 psi to about 76-77 psi. If you are down to 73, either you have a leak or you measure one when the tires were hot (driven on recently) and the lower one when cold (not driven for several hours).
If 80 psi is the recommended cold psi for your tires, by all means bring them back up to 80, but do it when the tires are still cold. If necessary, take a reading when they are cold and figure out how many pounds (psi) to add, then drive to an air pump and add that many, even if it takes you above 80. The pressure will always be higher when the tire is hot from driving, and that is OK..
2004 American Tradition; 2014 Buick LaCRosse
Homebase in the Ocala Nat'l Forest near Ocala, FL