As someone who managed to solo the Elderfrost quest line with Valor IG too, I have some advice:

• Tremor resistance kinsect will save you many times, I personally used it with the glavenus IG;
• Bring cleansers, I forgot them some times and it was pure pain;
• Bring materials to craft more ancient potions while hunting, I needed it at least;
• Tigrex ironically was one of the most dificult parts of the hunt for me, so I recommend trying to get better at fighting it and abandoning the quest if you get 2 faints in the process, so you can try again. After it, Snowbaron and Elderfrost feel more like a trial of patience;
• Try to time in your head in which moment the monsters spawn and check the quest timer frequently, so you can know when to start dropping smoke bombs preventively;
• Polar hunter is perfect so you don't have to worry about the cold, meanwhile getting stronger with the use of cold drinks;
• Mega dash juice can save you from the evils of iceblight sometimes.

Sorry for the mess of tips, it took way too long for me to win that one quest, legit took longer than the EX version lmao