Cookies will stay fresh in their heat sealed bags for 2-3 weeks.
Keep your cookies at room temperature. Allowing them to get too warm (sit in direct sunlight or in a warm place like your car) can cause multiple issues like breakage or butter bleed. Placing them in the fridge will dry them out.
When transporting, protect your cookies from bumps as much as possible. Placing your cookies in a seat rather than the floor is preferable.
You may freeze your cookies for a month or even longer. They will taste just as fresh as the day you froze them. To freeze, carefully place all cookies (still in their heat sealed bags) in an airtight container. The night before you need them, take them out of the freezer. DO NOT OPEN the airtight container until cookies are fully thawed. Doing so may result in condensation on the cookie, ruining the decoration.