Since it sounds as if this may be a pretty close call: I think that you've got three choices...
1. plug it into the separate 110 volt line...
2. Continue to figure out ways to make your current setup more efficient.
(Although I can't think of anything else to add to your labors.
)
3. Bite the bullet, and pop for the "full-bore/Big boysz" 50 amp upgrade...
Good luck with your decision and implementation!