From what I have seen with most of my females it is fairly easy.

I do so because I end up with a rat surplus during the winter (animals eating less) and offer F/T to my animals when they resume feeding and until I no longer have any F/T in my freezer.

Most of my females have been switching back and forth for 2 season in a row without problem.

Of course this does not mean it works for everyone this is just how it work for me.