No, I don't play loud, now, but for outside, street-corner gigs I never had volume issues with my Fender Bassman Export (50w valves, into that same Fender 2x15 cab...). Here's an old photo...
OK, for a really loud band, 100w (or that superb 135 Fender/Musicman amp...) would be more than adequate.
Just for fun, here's a photo of the Hiwatt stack our 200w head used to drive, as a PA, one stack each side of the stage (so four cabs...). 200w; we never ever lacked volume (and, for me more importantly: headroom...). Clean to the sky, and darned loud...
Yes, this lot filled the van, and weighed it down, too..!