Does the map of Barovia extend beyond the top and bottom of the map?

I’m currently running Curse of Strahd and plan on extending the adventure beyond the end of the published material. There are a couple of areas that the party have not gone to and I do not expect they will go to before finishing the adventure, but otherwise, I don’t want us to be just going through all the same old locations again; I wanted to add some new areas and extra content.

Looking at the map of Barovia on p. 35, I can see that the left and right edges of the map are likely the edges of Barovia, since the right hand edge is labelled A, which is where the party first arrive after walking through the fog (which I take to mean that going back in that direction just leads them getting lost and spat back out into the map, as per “Mists of Ravenloft”, pp. 23-24), and the left hand edge is likely more of this fog, given the description in Chapter 14: Yester Hill (p. 200):

This is the reasoning I’m using to conclude that the left and right edges of the map really are the edges of Barovia itself, and that there is nothing further in either direction (although, if I’m wrong about this conclusion, I’ll happily be challenged on that in an answer).

My question, however, is about the top and bottom edges of the map. At the top of the map is Mount Baratok and the various locations marked M. The bottom of the map is Mount Ghakis and a road that leads south from Amber Temple (although this could just lead off the edge of Barovia like A and road that leads west from Krezk, but it could be a road to somewhere else in Barovia). There’s nothing written in this adventure that implies that these are the edges of Barovia itself (yes, there’s the “fog effect” around the edges of the map, but I assume that’s just for style, since otherwise Barovia is a neat rectangle shape – unlikely).

Of course, I as the DM could just decide that these aren’t the edges of Barovia as that suits my purposes, and if it turns out that these are actually edges of Barovia, that’s likely what I’ll do, but I wanted to know if there was anything published about Barovia (likely from older editions of D&D, but if there is anything I’ve missed in 5e, I’d prefer that) that describe what might be beyond the edges of the map. Are there any maps in previous editions that roughly match up with the map I’m using that shows anything further north and south, or anything I’ve missed in 5e Curse of Strahd?

What is the connection between the Shadowfell and Strahd/the plane of Barovia?

I’m preparing to run Curse of Strahd, and one of my players wants to play as a Shadar-kai who is loyal to the Raven Queen.

In the adventure’s set up, it says (p. 9):

For obvious reasons, I’d like to know more about the connection between these Dark Powers of the Shadowfell and Strahd.

I’ve looked at the related question What are the "Dark Powers"? but it seems to be an old question based on old D&D lore (from 2e and 3e) that doesn’t help in this regard, because the Shadowfell appears to have been introduced in 4e (and remains in 5e). Hence this question about the 5e adventure Curse of Strahd and the 4e/5e Shadowfell is not a duplicate of that question.

Rather than focusing on the Dark Powers (since that would make this a duplicate), I want to instead better understand the relationship between Strahd, Barovia and the Shadowfell, especially if the Raven Queen is supposed to be in any way related to any of this. If it turns out that she is related to this, then this player’s backstory will have to include why the Raven Queen is sending their PC to ruin Strahd’s day (especially since, AFAIK, the Raven Queen dislikes sentient undead), whereas otherwise the “Raven Queen dislikes sentient undead” thing is probably enough on its own.

So, in what way is the Shadowfell related to Strahd, and the plane of Barovia (if at all)?

I’m chiefly interested in any 5e lore that might help me understand the connections between the Shadowfell and Barovia/Strahd, but 4e lore is acceptable as well. 3e and older lore I won’t shun if it can help in any way, but the fact that the Shadowfell didn’t exist back then implies that answers must contain at least some 4e/5e lore as well for such answers to be helpful.