Yeah I know what you mean, I'm lucky in the fact I can record the mix fine as the master out on the mixer just goes straight into my PC, so when my speakers trip out I can just switch my amp off and on again and it'll sort it. But only for about 5 minutes! If I'm stuck I could always just mix on the headphones but it's not quite as much fun9 times out of 10 this won't work, but this week with the lightning I had a few power cuts. I had loads of static and also the Soundcard not recording at full volume on the left stereo channel. I found switching the mains power off, unplugging everything, leaving it a while and plugging it back in wire by wire seemed to work. I probably just got lucky though.
You could always learn/turn to Ableton as a mixing backup, although I really find making mixes with Ableton is no fun at all.
Tried Ableton a couple of times, just can't get on with it. I think I'm just too used to Cubase now, I can't seem to even get started on Logic or Ableton.