In Mon's case the plug was pulled when all aircraft were on the ground as it happened on the normal schedule early Monday morning. With TCX I assume there's never a point in time when this occurs at this time of year so I guess if it was happening it would be planned for when the minimum no of aircraft are airborne. As for a/c being put on remote stands at present this could be just normal practice overnight (with a/c planned to be moved to piers in the morning), or airports could just be just hedging their bets just in case, with no knowledge of any CAA/govt plan.
With Mon, all ticket prices were hiked significantly about 24 hours before the plug was pulled (i.e. e-mail to all staff), supposedly to discourage bookings for flights that it was known would not go (although it seems the decision to fold the airline had already been made more than 24 hrs before the price hike).