I'm proud to inform you that my newest adventure, "Finders Keepers" is now available on DMG. I tried to make it deeply connected to the Forgotten Realms lore, so I hope you'll enjoy it, especially that 20th level adventures are not that common. You can find it here: http://www.dmsguild.com/product/215482/Finders-Keepers?sb=1
Thanks! That's the point - you might never reach 20th level! Take a break from your usual campaign, roll level 20th heroes and have fun! Then return to your regular game :)