I live in Edinburgh and I've managed to book theatre tickets in London for 29th Feb 2020 a week before NR and LNER announced that this will be a weekend when Kings Cross is closed for the remodelling and I should not travel! It looks like the only other option is to try Virgin Trains via Carlisle. They're offering Super Off peak fares for that weekend already. Does anyone think that they will ever offer Advanced fares on this route on that weekend, and if so, when are they likely to be available?