I played through it last weekend. Level 8 rogue. A quarter of the way through two of our players had to leave, so it was just me and my brother, a level 8 Warlock. We got all the way through, and beat the whole thing. Took two days of real time.
Of course, we got all the way through because my Rogue had acquired a Shield Guardian on our last adventure. His name was Hermon. Hermon did most of the heavy lifting, seeing as he could heal after a few rounds of resting. He triggered all the traps, carried me over spiked floors, and generally took a wallup of a beating throughout the tomb. He was squished by the last trap in the game, just before the vault. Managed to beat the Demilich because we'd had the Siren use Greater Invisibility on me, so the Demilich couldn't see me, and then she ran off so she wouldn't get knocked out and lose concentration. Sneak attack for the win. And since the Lich couldn't see me, it couldn't do it's instadeath spells. It knocked me below 0 HP once, but I rolled a 20 on my death save and popped back up for the kill. It was glorious. I had a blast, and had to beg our DM not to just kill Hermon for no reason other than he was covered in cheese. Technically, we used him legitimately, and the DM let us take him in. Thankfully, my brother's warlock is a Kenku who studied the Shield Guardian, so he can remake him (DM ruled it was ok). Took 75,000 gp to do, but it's worth it to have Hermon back.
Oh yeah, Hermon has my Hat of Disguise, and it makes him look like a Half Orc bouncer wearing a suit and shades.
But yeah, I'm going to run it here on Enworld, and I'm going to change some of the rules around. Like going for longer rest times (8 hour short rest, 7 day long rest) and keep track of rations, only allow one perception check per day if they fail a perception check, really force them to dungeon crawl it.