A character was hit by cone of cold and failed their save, and due to high rolls of damage, they are killed outright by massive damage and become a frozen statue. Fortunately, the cleric has Revivify prepared. We'd need to thaw the statue before casting revivify (assume the DM says so), and so we only have one minute or less to thaw the PC.
The obvious fast method would be by using magic, however by RAW, spells do not do anything more than their description, so if a spell does not have descriptive text that says that it melts ice, it doesn't. As far as I remember, even fire-based spells don't specifically say that they "release heat;" that suggests to me that fire spells can't melt ice, so firebolting the statue won't work.
The closest I can think of are spells that specifically say they set unworn equipment or objects on fire, thus it being reasonable to rule that they can melt ice.
Going by RAW, is there any spell that can be used to melt ice?
Preferably it can melt nonmagical and magical ice, but just either is fine. It also does not need to be a fire-based spell. Wish is also a too obvious answer since you can do virtually anything with it.
Per wall of ice, any source of fire damage will work
Wall of ice creates wall sections that are 100 cubic feet of ice each, and take 30 damage to destroy, or 15 points of fire damage (since it has vulnerability).
If I were a DM looking to rule on a player attempting to break through some ice, I'd use that as a guideline for how much damage it takes, and treat all ice as vulnerable to fire damage. (I'd also make it immune to cold damage, because duh.)
By RAW, this doesn't melt the ice, because the word "melt" is not used. And by RAW, this only applies to wall of ice, not to ice from any other source. Hey, maybe it's magical ice that has none of the properties of normal ice.