Riding on a failing bottom bracket - what could possibly go wrong?
Eventually your bearings will disintegrate and your BB will lose its ability to hold the spindle centred withing the BB shell, that will result in the crankset becoming wobbly, your chain will come off, your chainring might even go hit your chainstay and if you're lucky it will happen at low speed.

Here's a BB I personally exploded on my fixed gear commuter



Everything I described above happened and I would not recommend running a clearly faulty BB for too long.

I believe a BB using bearing cartridges might not fail as catastrophically as one with simple cages like the one pictured but I doubt it would end well in the long term.