Really? Coldest ice can burn more than the most powerful heat? You KNOW the most powerful heat is the sun right? 15 million degrees celsius?
At best you should have said 'than the most powerful flame' since flame!=heat. But that would still have been silly.
Personally, I enjoy the story.
I dislike some of the formatting (using their names to note who is speaking at the beginning of every sentence like a play script). It doesn't feel like a story when it's written like that.
And the fact that he is a fire Blizzard dragon... I feel that it is a name much more chunni than logical. If he had evolved to a temperature dragon or energy dragon or entropy or enthalpy dragon. I mean there are many ways to describe a super power that has control over temperature (hot and cold).
Since hot and cold is simply defined by human conventions, you can search for the exact wording on different comic inspired super power wiki sites. A "true" ice dragon is not limited by 0 degrees Kelvin. Nor would a "true" fire dragon be limited by warping of gravity due to an exothermic reaction approaching the limits of our reality.
So I feel like being todoroki is level 1 for understanding his power. It's not actually helpful to use both powers. Artistic yes, helpful? No. His goal, should be to control exothermic and endothermic energies or to effect reality in such a way as to cause similar results without the by-products. Such as destroying earth or venting the atmosphere or causing the apocalypse. A temperature dragon rather than fire ice storm dragon. Heck, you could call it a thermic dragon (Endo/exo thermic reactions). Eventually becoming an energy dragon, then finally a reality dragon to compliment ophis and rivalling great red.