Traditional Broadband is even less reliable - frequent short interruptions while Fujitsu are working to extend Openreach's fibre network. My local 3 mast is on top of the local exchange building (380m, almost line-of-sight), I don't know whether our exchange still has a stand-by pair of diesel generators but I understand that Openreach have been removing them progressively . Most likely scenario is a power outage - no power = no broadband, no phone, no mobile. I still have a gas stove with manual ignition - at least I'll be warm!