I did a perilous trek south from Nivalis in extreme northeastern Morrowind south to Necrom. I was saving frequently along the way because there are some NASTY customers out in that part of the countryside, both in terms of bandits and beasts. The trip got me thinking about how this compares to the Morrowind in TESO, given that the Tamriel Rebuilt project got started before Oblivion released and long before TESO was a thing, so I looked up a map of the current TESO:
Turns out the area I went through isn't even in TESO yet, it's the grey part north of Necrom, I cut a line south along the eastern half of that peninsula.
That map actually goes a little bit further north, you can't zoom out far enough to show the entirety of what's in the game at once, even in openMW, but that's almost all of it. It's a little hard to see because they don't exactly use contrasting colors on this map, but there is the path I took south to Necrom, more or less along the eastern coast of the continent (I was always close to the shore but rarely on the actual shore itself), plus the parts of Vvardenfell and mainland Morrowind I explored previously. I'm currently in Akamora.
I am consistently pleased with the content in the Tamriel Rebuilt mod. I was hoping this was simply more Morrowind and that's exactly what this is. I don't feel that this is a step down in quality compared to the vanilla Morrowind content. There are settlements, caverns, ruins, quest chains, encounters, etc. It's all been overall enjoyable and just feels like a natural extension of Morrowind. As you can see on the map, I have A LOT more to explore, plus there's more coming. There's no ETA AFAIK, but the next update to the mod promises to be the biggest ever and will be adding a big chunk of southern Morrowind.
Eventually, I'll be able to go to Narsis.