bethesda.net/en/games/deals/windows-10-pc
The platform you select determines where the links take you -- Steam games take you to Steam, where it says the sale goes through August 30, while PC games take you to Microsoft's store, where it says the sale is on for just 2 days. I saw discounts up to 80% off, but I didn't view the whole collection, so you may find bigger discounts than that.