Just stop overloading your core and transport networks. There is no excuse for either of them to run at 50%, you should always be able to lose half the capacity without service impact.
Core and transport network capacity is cheap. If you can't keep up because you didn't bother to keep the hubsites' HVAC upgraded properly either for CCAP or transmission that's not the customers' problem and they shouldn't suffer.
Stop cheaping out on the transport network, stop cheaping out on the peering bandwidth to LINX. You guys run a fraction of what your peers do and, no, Aorta peering in Frankfurt, Paris or Amsterdam isn't a replacement.