All those potential price shifts are factored in to the current price and probabilities of outcomes of the lead up games you mention
The key principle when hedging is the same as when punting - do you think the market has the price wrong? If so, ensure your hedge bets exploit the overs.
If you think the market is about right, then there is probably no point in hedging, (as you are just exposing yourself to another round of vig) but if you must because the amount of money at stake is quite high, then whether you do it now or do it tomorrow is no different than simply having a bet/gamble on the outcome of tonight's game.
Surely on a promo where you get $101 on a "should have been sub $12" fave is a fair time to hedge regardless of "vig" on the other side...unless you're a regular $500 a bet punter I can't see how it's possibly a bad idea to hedge when you had such +++EV to start with thanks to promo odds?