Slightly bigger than a 100 seat bar, but...
I used to work as a live audio engineer for the sound company that got the annual contract for all the Christmas parties at the World Trade Center Boston. So every year right after Thanksgiving they'd convert their 20,000sq.ft. exhibit floor into a party space, & we'd load in a fairly substantial flown PA system...plus a few spare cabinets in case of emergencies. Then for the next 30 nights I or one of the other staff engineers would mix a different cover band for a different corporate office holiday party.
One year I got called to sub on bass for a band that was booked for one of these parties. Since I had access to all the PA gear we had on site, instead of bringing my bass amp I just brought an Intersound IVP preamp, then dragged a spare Adamson 3x18" subwoofer & the matching 3-way hi-pack box onstage, along with a Crest 10001 power amp. 5,000 watts rms per channel feeding a trapezoidal stack almost 10' tall; >118dB SPL at 10 meters from the front of the stage, from 20Hz to 18kHz.
And then I had to play "Celebrate" and "Jingle Bell Rock" and a ton of other crap.
But the look on the drummer's face was worth it.