It can be frozen just like regular butter. It will look like regular butter when it is frozen not like the creamy sauce. When you re-heat the milk solids might not be in suspension with the rest of the sauce. It should taste the same but may not look as creamy as it was before.
I know the frustration! I have come across a couple of tips while doing my research. Sifting the flour may help to make a lighter end product and if you are using a coarse meal or flour, add 2 ½ tsp of gluten free baking powder per cup of flour to help the flour leaven. If I find anything else, I will let you know.