From the DECV website:
Between late February and early March our Exam Centre Coordinator will send out material to our DECV-based students asking where they wish to sit their exams. Students may apply to sit their exams at the DECV in Thornbury or at another school or institution. In certain prescribed circumstances students may apply to sit their exams overseas or interstate, or apply for Special Examination Arrangements. In these instances supporting documentation will be required and approval is at the discretion of the Victorian Curriculum and Assessment Authority (VCAA).
Students studying at a mainstream school should be aware that their home school is responsible for all VCAA Examinations arrangements, including subjects taught by the DECV. Home schools are responsible for applying directly to the VCAA for any Special Provision requirements. School supervisors should inform the DECV of any approved arrangements that are in place.
You would definitely have
at least one supervisor with you during a VCAA exam. Doesn't matter if there's 1 student or 100. Distance or not. I'd be leaning towards the single supervisor for you, though. Yes, you'll most likely be in the exam room on your own unless there's another subject exam running at the same time that students at your school complete - then it may be combined.
Do students commonly complete subjects via distance at your school? If not, i'd be raising it with somebody ASAP at your school just incase.
P.S - Good on you for doing Informatics and choosing to still pursue it even with access limitations!