The first sentence is contradictory and therefore doesn't make any sense. Nonetheless, here is a word for word rendition. 1. Every day thousands, sometimes tens of thousands arrive in Germany over the/a weekend. 2. But then all of the infrastructure designed to cope with permafrost would be wrecked. 3. Indeed, the migration flow we're seeing today is just the tip of the iceberg, compared to what will happen given the temperature increase of 2 degrees. P.S. The last sentence uses the word "толика", which I have never heard of and find very odd to use. So I suggest you avoid using it in speech or writing. Cheers!