After I upgraded to R7 and wrote the license to my laptop I've had no unnecessary license updates where as on 6.5 and the old authoriser I used to have to update my licenses a lot. It got pretty annoying and I knew that if I was somewhere with no internet I'd be screwed (Partly the reason I got ableton)
Aside from upgrading to R7 I'd say just prepare a little better next time and you won't have the embarrassment. Any reason why you can't update your licenses (if needed) before you get on stage? Perhaps while the checks are all being done? I understand the frustration though.