If you only have one copy of your materials for a presentation, I'd say that you're unprepared for said presentation. What if GitHub was up but the network wher

If you only have one copy of your materials for a presentation, I'd say that you're unprepared for said presentation. What if GitHub was up but the network where the presentation was being given was down? Would tethering really provide for a smooth presentation? What if tethering was overloaded due to all the other people "listening" to your talk using it instead?