A perfect Manhattan with bittersweet liqueur rather than aromatic bitters and a balancing dash of sweet maraschino liqueur.
If you can't obtain Picon...
I love this drink…just made me a nightcap….and I do have a bottle of Amer Picon that I keep refrigerated but “all truth told” , ordered it from Belgium during the pandemic….seems to still be wonderful?? I used my staple, Bulliet Rye…and both Martini and Rossi vermouths..
Our Amer Picon sits happily on our bar shelf, unrefrigerated. And we don't have air conditioning. Our current bottle, getting very low after about a year, still retains its freshness. Maybe worry more about your sherry, vermouth and aromatised wine. And yes, a great nightcap...not too strong.