Sweet cocktail suggestions to use up this Carpano classico?

I bought a bottle of Carpano classico but like so many others complain, it’s not the sweetest sweet-vermouth. It’s downright bitter, which ruined my first attempt at a true cocktail.

What are some ways to doctor this vermouth up so that it’s fairly sweet and easier to drink? Ginger beer & vermouth? Another cocktail mixer & vermouth? Soda/cola? I want to drink it instead of throwing it away.
Even being chilled in the fridge doesn’t help.

Thanks!