So yeah this is a really awesomely painted piece with well thought out composition and colouring.
The lighting is the biggest factor in the visual impact of the picture, and you've got some good stuff happening and a good clear light source, but also it could use a bit more reflection. The cave is ice, which reflects very well, so: -Brighter glints and highlights on the dragon's heads and wings, -The walls and floors could have a dusting of glitter, -The icicles could shine. These are lust little point that would bring a bit more life to the pic. I understand these are all things that are added in with editing and practice, but keep them in mind. Great textures on the dragons, I admire the scales and spines, (there's a little bit missing from the tip of the purple dragon's wing.) And you've got excellent shading skills. The background could use with some texturin' up with more angles/cracks in the ice. Ice is annoying to draw, not-quite-stone but you have a good grasp of it's dynamics here. I like the outside, the aurora and blizzard blurring together are great atmospheric elements. Perhaps the mountains might be a bit spikier/ more angular but other then that its great!
Overall, a really amazing piece, well designed and executed featuring some beautiful dragons!
A very exquisite image I feel, it is nice looking and as much as the whether may seem frightful cold, the feelings and love are quite warm. I like seeing dragon togetherness like this a in this ice gave alone, as an aurora shines in the distance, it is very well done image I feel.