Glancing through the various Tech Support threads, I see the RED Team has mentioned that the upcoming patch should fix a number of issues in the main game, and HoS. As such, I would assume it will be quite a large patch.
And they've never said it would be the last patch. Just to make it clear, when I said "last patch", I meant "most recent patch". 
Any news when the 1.13 patch is gonna be released is it gonna be before Blood & Wine is released or will it be released on the same day oh well any info would be great thanks.
I read somewhere (can't remember where, probably on these forums) that the patch will be released a few days before the DLC.
Probably a few days before. During doesn't make any kind of sense, and if it's after, it would cause all kinds of conflicts for those with B&W..