I don't think that's how a service agreement works. If I'm paying for a certain bandwidth and latency, I should get that (to within reasonably improbable outages) if I use it 100% of the time or 1% of the time. If the ISP can't keep up, they should be penalized for it or change the labels on the thing they're selling. You don't see a cloud storage provider saying "you get 100 Gb of storage, but only if you don't use 99 Gb of it."