I went at level 11 today on Master with Onmund as follower. It's way too hard for this character ... I got some kills on Ash Spawn, but only with some incredibly cheap play (i.e. running away and depending on followers). Given that obtaining the Black Books means no followers, I'm pretty much certain that I'll be scrubbing around this and going back later.

im level 1 and its working out well.

What do you do?
Run right past the enemies?

Technically you could be 100 Sneak and still be level 1 ... could have a lot of good enchantments as well, providing reasonable health and stamina. Still sounds miserable though.

That's my current character in a nutshell. He's been very happy so far!

20+, surely. I went as low as 6 and it was... extremely difficult, even on Novice. One of the first quests in Raven Rock (The mines) pinned me against Deathlords. I only survived due to personal experience. And the priest? I was on a caster and had to sneak-archery him down. Took 15 minutes to kill him.

Definitely not an expansion to head into immediately.

As a matter of interest, care to share your strategy? I got past the wight & scourges, but the first Deathlord one-shotted me, and it was at that point my character crawled back to Skyrim.

I was a Dunmer mage who had the impact perk. That was the extent of my strategy. Though one time I had no mana or potions and luckily, it was a bow-using Deathlore. I simply used a pillar to dodge behind. He'd hit me, and my health would immediately go down to like 2%. In which I'd spam healing for a bit. Otherwise I just kept throwing (non-impact) fireballs at him as my mana allowed.

Oh, I take that back. I DID have to outright run my ass away once.

So running and placement are paramount.

I also died around twice, which isn't bad considering I was under 10 in a 24+ dungeon.

Sneakers would have an easier time, not sure how a melee would do it.

Also note that the Dragon Priest is technically skippable, you don't NEED to get "past" him for anything. The door to the black book is on the same side of the room as when you enter. I saved there and tried for using a bow/sneak tactic. Took a really long time, and I saved after every shot. Thankfully he doesn't regenerate.

This was all on Novice, too.

Tried to do it on a level 15 and the ash spawns were not fun (on adept). I figured I shouldn't bother if that was what was happening right outside of Raven Rock. I ended up playing it on a level 50 dual wielder on expert, which was on the easy side, a few hard parts. After going through the Temple of Miraak I was glad I didn't try to force my way through on an underdeveloped character, though.

Depends. I sent my poor lvl 7 nord and he didn't know what hit him, on expert no less. Yet, while lowering the difficulty at a few key places, I can't explain how satisfying it is to finally returning to Skyrim after completing most of the larger quests from the island. The strongest of swords are forged in the hottest of fires and all that. I use dragonshouts more now, because I had to, and it just all round feels more rewarding because of the difficulty.

If you get frustrated easily, I wouldn't recommend it, but it is a whole lot of fun to throw yourself into this dlc under-leveled and force yourself to do what you have to do in order to finish it. You'll die a lot and have to lower the difficulty now and then, but I had a whole lot of fun.

I took my LVL 9 Nord there and took a beating. The Ash Spawns and the Fire Spriggans took hair-line impacts to their damage bar with my attacks. It was laughable. I swam in the ocean past the Farm and Ash Spawn event and headed up to Falbtharz to get the fabulous Skaal garb.

I was able to lure the Rielkings and the Dwarven constructs into the propeller blades in the first section before the gear-jump chamber. I grabbed the Skaal apparel in there and B-Lined it back to the front door. I'm going back to Solsthiem in about 15-20 level-ups now that I have what I came for.

The Reavers were like regular Bandits and the Silver-hand at low levels. The Reiklings owned me a few times after about 3-4 hits. Even the Ash hoppers are on the same page as Snowy Sabre Cats. Yikes...