1. This is all down to cost, we run multiple internet providers, from multiple sites, all with cross connects; expensive but the chances of losing them all is very low, and even then we have ISDN lines at every office and site.
On the cheaper end, a cellular data link of some kind that can be fired up if the main connection is lost.
2. Depending on your size or requirements, running another NPM from the other site, so if one site is lost the other is still monitored and it can alert you, or have you seen the Solarwinds High Availability or even the Additional Polller Engines?
We use HA and APEs across our DCs.
How about using SMS gateway ?Remote monitor that will work even if the power is down...
That will be easier then moving the DC ..