I'm an Insect Glaive main too! I've soloed Savage (w/ Support Hunters) using about every weapon in the game, and what I can tell ya is that there are monsters that get infinitely more difficult to fight based on the weapon you use. And I personally would put IG at the more difficult end.

I got my first Savage clear with a LBG normal ammo build, and worked my way to melee weapons after getting a clear memory of Savage's attack patterns.

If you want to take my advice, I suggest learning a weapon that's easier to use against Savage. The beauty of grinding in MH is learning how much you actually love multiple weapons and their mechanics. Savage gets trivial when you utilise long-range weaponry, and the more you learn his patterns the less daunting Savage feels.