It normally take me around twenty minutes to get all my gear set up and running, whilst the drummer takes about an hour,
and the lead guitarist takes forever farting around with all his gear, and I would imagine this is pretty much the norm for most bands.
So why would you want to tune up at home, when you have so much time to kill, you could tune up over and over again while you are waiting.
And you can have one last tweek as you take the stage, with a floor tuner permanently plugged in, takes around thirty seconds.
Buy yourself a tuner!