Butter and margarine freeze perfectly. I generally stock up during sales and thaw it as needed. You just have to make sure it's wrapped tightly in the foil, to prevent oxidation. It'll keep at least 6 months, probably more if you don't have a self-defrosting freezer.
Thawing butter does take quite a while, however. I usually give a package a few days to thaw fully. If you need butter in a hurry, you can always put it in a Ziploc bag and fast thaw it a bowl under running running water. Or, just soften it in the microwave.
We've frozen Margarine all my life. My Mother would buy margarine on sale and freeze it for our big family. We just pulled it out of the freezer as needed.
We always, and still do, freeze it in the box it comes in with no extra wrapping needed and it is just as good 2 years down the road as it is when you bring it home from the grocery store. Now, different brands may not be as good or freeze as good either. I don't remember what we used growing up, but now, we ONLY buy Blue Bonnet Margarine (original/regular, and never the lite).
I buy four packages fo butter and freez them as i need them. I then take a quarter of a stick and put it in container and let it thaw out overnight. I leave it out until it is gone and take out another stick of butter from the freezer. I have no problems witn freezing or thawing butter.
If you ask any of the margarine manufacturers, they'll tell you NOT to freeze margarine because of the high water content. Upon thawing, the oil and water will likely separate. It'll look bad and not taste as it should.
Butter, on the other hand, can be frozen, because of the high fat content.
Unfortunately preheated fats (processing with heat) and then freezing the goods will turn most of the fats into trans-fatty acids. That is useless stuff for our system. I freeze my raw butter from my grassfed Jursey. No issue!