I've seen arguments suggesting that old russians were well-accostumed to using alcoholic beverages and pork in order to survive the cold, so i contest that.
That argument is a bunch of folklore given that Islamic law never stopped Muslim cultures from drinking (distillation was perfected by Muslims and the word "alcohol" is derived from Arabic as a result, the Arabic drink arak spread globally, etc.), and not to mention you can devise a loophole that mead is acceptable. Even the issue of pork isn't necessarily a problem, since the average Russian peasant doesn't need to stop farming pigs, he just needs to say that there is no god but God and Muhammad is his prophet and everything will be okay since at least his knyaz isn't eating pork. Not to mention it fails to explain Volga Bulgaria.