Looks like DoS 2 reached 1 million sales by around 2 months of release. 500k for Solasta is looking better and better.
(I don't think Solasta will reach the same numbers as DoS 2, but even this is not an apples to apples comparison... Larian was well known when it released DoS 2. There is no real apples to apples comparison, but it might be interesting to compare to Divine Divinity lol).