Bear in mind that there will be solicitor & asset manager costs to be added, may be redemption fee & closure costs. Also depends on the loan to value how much he borrowed against the house. You then have any subsequent charges (Land Registry will show this). The lender has to attempt to achieve the best price possible so it would be rare for it to go straight to auction unless there are problems with the house. Lots to think about.
Lots of the big auction houses advertise in conjunction with agents on Rightmove & Zoopla. eg Hamptons estate agent is affiliated to Countrywide auctioneers (renamed now but you get the point). In the listing it will give you auction contact details inc date; normally the estate agent's role to facilitate quick sales if they are able to exchange prior to the auction date.
So I'd suggest you look online first...you've a pretty good chance of tracking it that way.