If you have the key within your disc carrier, you should be solid.
I think you can download it and still play single player even on the remaster, which was solid btw.
There are also pirated versions that you could utilize given that you already own the software.
There are also 3rd party moded communities like path of Diablo.
Path of Exile 1 & 2 are crazy good and true successors to Diablo 2 if you haven't checked those out. They blow Diablo 3/4 out of the water in gameplay.
WE NOTICED YOU RECENTLY JUST BOUGHT A BASKETBALL, WOULD YOU LIKE TO SEE ADS OF BASKETBALLS EXCLUSIVELY FOR THE NEXT YEAR ALTHOUGH YOU ALREADY BOUGHT ONE?
Damn dude, give mom a hug and let her know that you see her, and we all do too. She did well and so did you.