TL/DR – it should *likely* not be a problem because (1) we can plan; (2) the lighting load is modest (maybe 10% of total grid at most. (3) We have enough fast acting supply options that can manage.
(action 1/3) Don’t panic. Good that we’ll have candles ready just in case!
(action 2/3) It probably WON’T help to switch on ACs/loads since it is the FALL in demand (+rise 9 min later) that matters. The % change for 130->120 GW vs 120->110 is small.