Those closer spots - do they have any cafe's? Perhaps scope them out and see if they have A/C and good kid friendly menu's. In your emergency bag make sure you have plenty to keep the kids occupied - things like colouring in, ipad/DVD player if you have those, books, fav teddy etc.

Try to see if there is an alternative route Bendigo.

IMO, Ballarat isn't that extreme - you never know what's going to happen and getting out early is important. But do keep in mind that Ballarat and Bendigo can also be high risk areas so BEFORE you get in the car and go anywhere, check the CFA website (or iphone app) to see if there are any warnings or fires for those areas (or along the way). The bigger towns are good though because you have more services (shops, accom, eateries, play centres, etc).

Also have a chat to the local councils, they may set up something. Do those closer towns have a library? Or Community Building?

If you are planning to leave early, don't forget to have a bag packed with anything you might need.