sounds about right if we have 14 hours instead of the regular 7. Good to see you are taking this endeavour seriously and putting in the hard yards.
Use roadie or MTB? Former easier to ride for a longer time but not great on dirt. Need to think where the controls will be located - e.g top of dairy farmers hill to say top of stromlo is probably quicker by roadie even tho more direct by a MTB.
I was assuming MTB as our options and route aren't limited.