Using ray of frost to free water is something that in dnd would in most cases be left up to dm interpretation in heavier rp games most dms would let something like that apply just most players for games do not think outside the box. The idea behind the game was to make it similar to dnd where thinking outside the box is encouraged. Thus several mechanics. Not just ray of frost where this could be used.
I would leave this in too.
But I would take a look at how much blood is spilled from every low damage attack. It has been exaggerated in BG3 just so you have more surfaces to manipulate.
You should have to make a choice between A) Hit creature as in PhB, only damage no surface OR B) Target the terrain under the opponent to make them roll Acrobatics or fall prone. No damage AND surface, that's just overpowering the cantrip.
And I would make sure the area frozen by a cantrip is small enough to not turn into AoE i.e. only under a single creature. There are more powerful spells that cost a spell slot and can manipulate larger areas. Burning Hands, Sleet Storm
