Truth: This is extremely unlikely. The success of an online auction depends on buyers having access to inspect the property before placing their bid online. Access is usually given through scheduled open house “previews”, but can also be done by appointment.
Although it does happen, it's unrealistic for you or your seller to expect that if you use an online auction, someone from another state or country is going to start bidding without ever visiting the property.
An online real estate auction will be successful, when you understand that the online bidding automates negotiation with the local buyers you've attracted through your marketing (MLS, open houses, yard signs, etc.).
And, yes, it does happen that non-local buyers sometimes get involved, but they either have someone locally they are working with or have another means to perform due diligence.