nylons and paper towels will dry the bird out real fast which then freezer burn start then you have a very unhappy taxidermist.
place it in a plastic zip lock bag and lay it in the freezer and protect the tail
shooting a CANON 7D II
Double plastic bag. And as for time to the taxi that isn't important. Get it frozen as fast as you can. If you take it to the taxi the day you shot its and he has a 6-8 month turn around guess what. You bird is sitting in his freezer for 5-7 months. I have 15 birds mounted and some sat in my freezer over a year and look just as good as the ones I took him hours after I shot them. Double plastic and get it frozen. Then you have the time you need to choose a taxi