Kalium, ignore any info you read on overwintering. Sometimes the best flows are in winter in Queensland, depending on winter flowers in your area. Remember bees forage at about 14C, so they basically don't stop here except for the odd cold day.
At times queens will scale down brood rearing if there is not enough nectar/pollen coming in, but that can happen any time of the year. They are more likely to need back up stores in a big monsoon than a cold spell. But as Amun says it is very rare you will need to feed. Look around the paddocks and you'll get familiar with spotting what flowers come out when. A weak hive that can't afford to send out foragers might benefit from short term feeding to break the cycle, stimulate more brood and hence have more foragers to become self supporting.
We have our own issues in QLD. We don't have to prep for months under snow but we are likely to have all our hives wash away in a flood, blow away in a cyclone, or get eaten by bee birds.
When you extract, leave a couple of frames of honey in the hive and you shouldn't have trouble with starvation. If a decent flow is coming in I don't mind taking all capped frames.