Corn is pretty resilient. Except to all the bugs that would be migrating south, and deer, who eould also be migrating south. And it takes a while to grow
Aha very logical that the south will be cover in snow while little norther then that it's clear from snow. Also, Israel, India and qurir should have resistance of the snow (the south of India)
The thing is, they didn't forget about India because the areas merchants would usually use are inaccessible due to snow and ice, so they would have to take longer, harder ways to get to Muscovy.
Those are MOUNTIANS that means they have high elevation, and some of them get snow already. And as I said many times before, this is far colder than any winter in the past, so yes, the snow would fall there