More importantly, if Stoke was so far down the list, its a wonder that he bothered to fight a By-Election there in the first place ?
He has a history of fighting impossible seats. He tried to gain Bootle in 2005, 2010, and 2015, as well as a by-election in Saddleworth in 2011. But he still far off his previous masters attempts ( Farage ) which, if memory serves me correctly stands at 7 or 8.
To answer your question directly, I have found the following website, which may be of help :::::
http://www.electionpolling.co.uk/battleground/targets/ukip