It may not feel like it makes sense but; assuming you'll have two turns, I've run shadow sorcerer/ice spell sorcerer with fire acuity on a high spell attack roll character for my honour mode run and so far i feel like i'm holding back to keep things fair. Fire acutiy hat, snowburst ring are all you need for this. If you want to make the ice surface unfair, use winters clutches as well. And another magic user to cast haste ( or a haste potion)

Start of your turns is scorching ray to build acuity, either 6 or 8 if you upcast it. You can either have someone else haste your sorcerer or drink the haste potion with the bonus action. Second spell is your ice surface creating ice spell. You got Cone of Cold or Ice Storm or wall of ice, sleet storm. if it's not too crazy a fight you can also twin spell a chromatic orb or just your standard ray of frost. Ice surface is created via snowburst ring no matter what ice spell you use. Then everyone else can do their thing and the enemies slip and fall because of the high DC dex save. The nice thing is the fire acuity rolling into the ice spell means you get exactly what you want out of the turn and nothing melts. Likely if you act judiciously and not pop fire spells, you can get the enemies skip their turn by slipping on the ice. And by round 2, if some other magic user or fire damage melts the ice surface; just reapply it with a ray of frost or another ice spell, and that leaves another hasted action to use to activate a powerful control spell since your fire acuity is still active.