County office specialty plates

So I recently purchased a used vehicle through a trade in at carmax at the end of november and purchased some specialty license plates that day as well. Carmax has a 30 day shop around deal, so I found another car I like better and will be picking it up this weekend. Since I have to go through the whole process again, I’m wondering how long will the county office hold my specialty plates, since I’ll have to wait longer now until I get my registration stickers in…