Depends on mood / time of the night.

Bad day / almost time to go to bed ? I kill reluctantly the first 2 then if I see him pull just 2 again I quit cause not in the mood to waste powerful CDs and take 30min to do what can be be done in 15.
I have been playing for 6 years and it only happened 5 times, 2 of which in HS when SMN was all about the 1min CD for AOE and nothing between so you would absolutely want a big pack or it would feel super frustrating.

Normal day / beginning or middle of evening ? I sigh and begin "casual play" mode where I mostly solo target to still have it engaging for me (still doing more DPS than most pugs on 3 targets so it is not really hindering).