I'm in the same boat this week and wondering the same thing. Just add more wort? Or throw it in the fridge, decant the old stuff (lazy unsettled yeast) and add fresh wort? Trying to step up from 2 cups to 2L.
Fermenting: Azacca Oat Pilsner, Egregious-ish, Barrel Fermented Dreg DelcoLambic, Sacch Trois Helles
Drinking: RIS v7, Doppelbock, RIS v6, Carrot Blossom Cedar Mead, Sauerkraut Fermented Gose, Gueuze, Brett Blonde, Kriek, Saison, Sour Blonde
Barrel aged: Rye Barleywine, Tripel, Wee-Heavy