I've amassed hundreds of potions in my travels. What's the best way to make money from them, considering I store them in a mod-added player home in Riverwood?

The best way to make money from potions is to make your own. Custom made potions can be worth many thousands of septims, while the standard ones are a lot cheaper and are best used as intended, i.e. by imbibing.

That said, all potions you don't need you can sell to an alchemical vendor or, if you have a merchant perk in the speech skill tree, to any vendor.

No, I have lots of potions gathering dust in my player home, including custom made ones. I just want to get rid of them

Didn't know about the merchant perk, thanks for that.

To avoid traveling to multiple vendors to sell dozens of potions, I like to find a vendor I can train with: Florentius or Saurine in Dawnguard, for example, or one of the Alchemy trainers. Once I train with them and they have more $$, I dump all my potions...and then go make more.