As we're heading to SL300 my end is now going up, but i managed because I rarely swung unless it was going to count, and i wasn't rolling, so i wasn't using stamina on dodging.
I've gotten so used to dodge rolling from 99.99% of my invasions being a fun game of "Dodge all of the castings" so I almost instinctively roll for most attacks.
People don't cast spells at me very often. 3-6 dark bead, or 3 wrath. That seems to be most people's budgets, which is easily handled with fat roll and low stamina.
Then my luck is better than yours I had an earlier encounter of the sort today in the painted world. Guy had 9 wraths, and tried to spawn camp the bridge.