I think Sleet Storm also has some options. IIRC you can use a fire spell to melt the ice surface then use a lightning spell to get the wet/lightning combo as with Create Water (or just use the water surface it leaves at the end of the spell anyway in combination with a lightning spell).
Yes you are correct, frozen water, aka ice :P can indeed be molten back into liquid from via fire. You can repeat this process of turning water to ice, with fire back to water, without end it seems.
And yes, I forgot Entangle’s vines could also be set alight. Plant Growth also creates a fire surface, though admittedly it doesn’t seem a very good use of a level 3 spell slot, whether on fire or not!
While it's definitely a combo, it doesn't really strike me as a very damaging/useful one. The fire proceeds to only cause an average of 2 dmg and instantly removes the movement disadvantage.
