Park your new stuff in scheduled so it's sitting there ready to go when we get extra freebies.  You can edit the start date in scheduled so if they're not ready to start at the right time you can easily change it.

If you've still got one cycle to go when the freebies come up, you can remove auto relist so that they drop into unsold and can be relisted, or you can change the duration so they end during the promotional period.  It won't always work but it often will, especially if you spread your listings over the entire time that they give the extra freebies. 

For example, if something is on 10 days and it's on day 6 of its third cycle when the freebies start, you can change it to a 7 day duration and remove AR, and it'll drop into unsold on the second day of the freebies.  If it's on day 4 when the freebies start, change it to a 5-day duration and remove AR. 

Just remember to change the duration back again when you relist, but you can do that easily enough with bulk edit - so long as you remember that you can only edit to a longer duration in the first two hours after a listing starts.  Yes, it's all more work, but a lot can be done with bulk relisting/editing, and it's either do extra work or pay extra money for a store or listings.