To be fair, there are two different issues here. There are many ways to skin a cat on small stages or in pub corners- for me, the less of anything to carry and clutter the stage the better, but any of the options here will work.
However, there will always be bad sounding rooms, and there is very little to fix that. Changing your set up because of one gig might be a bit of an over-reaction if what you do works for the band everywhere else. Learning the best compromise, or just putting up with the crap ones is sometimes the best option, as nothing will likely work in the space! I know quite a few regular venues pretty well and know which rig to bring and how to set it for each to get the best results, but even then sometimes you just can't win. I played a venue last night which has always been overwhelmingly muddy onstage even with the bass amp switched off, so just took a tiny amp to throw the top and mids to the band. I don't know what was different front of house, but it was completely the opposite, like the room just swallowed the low end up, and I wanted for a bigger rig onstage (didn't want to ask for more in the monitors, given how it usually sounds!). I also have a show next month in the worst sounding venue I've ever played. From function band setups to a huge hired in PA, that place just can't be tamed. It's run for private functions and ticketed events, but the sound in there is criminal. It would be difficult to treat due to the size and shape, but it desperately needs some trapping and absorbers somewhere in there. Given the amount of events they have through, the cost could easliy be swallowed too. ANYWAY... point is that it just sounds terrible. Any sound in there is awful, no matter how you try to coax it. Electronic drums, in ears, and silent disco headphones for the audience is really the only way, so I just have to accept that it's not going to sound very nice that night.
I've actually considered making amp stands and stage dressing of broadband absorbers which would at least clean up a little of the sonic mess which can fly about, but that wouldn't be practicable in some of the small local pubs gigs anyway.
If what you do usually works, and you tried to compensate every possible way, sometimes you just have to accept that you can't beat the room!