..... I know that they left Tasmania in 1910. Christiana travelled to Sea Lake in Victoria without Isaiah knowing where she had gone and he eventually returned to his farm in New Zealand.
* What evidence do you have that Isaiah OLDBURY returned to NZ, and specifically to his farm, after 1910 ?
Sale of Isaiah OLDBURY's property in New Zealand > acreage at Chaney's ("Empire Bridge") and a property at Tuam Street, Christchurch, took place in
March, 1909.
https://paperspast.natlib.govt.nz/newspapers/TS19090306.2.64..... in New Zealand and then look for sales details for Empire Bridge Farm.
The following appears to be the first of the "for sale" notices >
https://paperspast.natlib.govt.nz/newspapers/LT19080529.2.93.1 ... with further advertisments appearing from November 1908 ...
https://paperspast.natlib.govt.nz/newspapers/LT19081104.2.78.4..... I think initially I need to follow through the idea of whether or not you would need to be physically present on a certain date to fill in the Electoral Roll paperwork in New Zealand ....
NZ Electoral Rolls :
Isaiah OLDBURY's first appearance on an electoral roll on NZ was > on the "Kaiapoi *Supplementary roll (Canterbury)" of 1908 : [* This was a roll made up of persons who'd not enrolled in time to be included in the Main Kaiapoi roll, before it went to print. ]
It does not necessarily follow that just because Isaiah OLDBURY's name appears on the 1911 roll at same place, that he was actually residing in New Zealand. Often names were carried over to a later roll for a variety of reasons (and even deceased persons might be included).
One should therefore not place too much reliance of these rolls being absolutely correct - they're a useful tool but it's wise that they are used in conjuction with other information. They are also NOT a census substitute (NZ does not have published census records available.)
~ Lu