If the Internet shuts down for just a week, be rest assured Bitcoin will survive it and if it goes beyond that, I can't tell exactly but I believe possible solution will be formulated but it will take some time, it may not be immediately but it may happen just like we had with COVID 19 years back, it was a global epidemic without a cure as at the time of outburst but after awhile it got controlled and today it's not one which brings things  a halt again as before.

I think it's better to look at thr bright side of Bitcoin and the opportunities we can get with Bitcoin than focusing attention and energy of such presumptuous scenarios because literally the world has gradually grown pat that and it will only  be assertive to keeping your taughts in such a mind frame, it will be better to refocus on the good ahead.