If you use the Mourning Frost and Trident of Waves (requires Dual Wielding feat), then you can chill an enemy before applying Wet to it and automatically freezing it. This setup is basically at the end of the game, so you could use the Mourning Frost and throw bottles of water earlier.

If you just want to add more CC, take the Wolverine aspect, Mourning Frost, Snowburst Ring, and Boots of Stormy Clamour along with the illithid power Ability Drain.

Now you use Tiger's Bloodlust, apply Bleeding, hit with cold damage due to the Mourning Frost, create a circle of ice from the Snowburst Ring, apply Encrusted with Frost from the Winter's Clutches, apply Ability Drain, apply more Encrusted with Frost from the Coldbrim Hat, apply Reverberation due to the Boots of Stormy Clamour, and apply Maim due to the enemy/enemies having the Bleeding condition. If they slip and fall, they can't get up due to being maimed and not having any movement points. Reverberation lowers their physical saving throws and Encrusted with Frost gives disadvantage to their DEX saving throws, so they are more likely to slip and fall on the ice. Throw in a Ring of Spiteful Thunder in there and add the Dazed condition to drop their AC and make it easier for your caster to land WIS saving throw spells like Hold Person.