I can only answer part one.
To that I say, it'll be very, very hard at this time of the year.
Next, I'll go on to give you this link: http://www.weatherzone.com.au/long-range-forecast/28-day-rain/tas/central
From that I suggest that the 26-29th look pretty decent:

Next, you need to a look at the right hand column, and look at the long wave progression, This will tell you when the weather will hit the metaphorical fan and when you should consider bailing out:

Wait until next week, then you'll know how stable that gap will be.
This is very, very simplified meteorology but, IMHO, will double or triple the chance of good weather as opposed to not using it.
I used this method over summer and was able to nail a week with incredible weather.
Caveat emptor.
-icefest