Do you think we can infer that many of the Tories who haven't abandoned ship are soft remain?
Many will be soft leave too.
Or more accurately simply not arsed either way about Brexit.
At the EU elections Ashcroft pointed out the main three reasons Tories had for voting tory were 1) they'd vote for a donkey with a blue rosette 2) the think the party is more competent than the others 3) because they though policies other than brexit were more important.
So Tory loyalists who DID vote at the EU elections were somewhat indifferent to what was going to happen at in the EU parliament.
Add to that I note the turnout for the by election was 10% higher than the EU elections.
As I said before, those people who stayed at home for the European Election were much more likely to be even more indifferent to Brexit than those who did vote. Thus if that held true you'd expect support for Labour and the Cons to perhaps be higher at this by-election.
And strangely enough, the pattern of voting might well suggest that's what could be happening. We don't know this for sure but it would be consistent.
Also you could be seeing Tories who value Westminster much more highly than anything else (all the guff about Parliament taking back control hit a cord with someone didn't it). Thus whilst you might want to 'punish' your party at locals or the EU's the desire to do that 'when it really matters' aka Westminster elections, might not be nearly as strong because well... ultimately because of the Farage Paradox and they don't fancy him as PM precisely because he's only got one trick who is using Brexit as a Trojan Pony for fascism. Don't underestimate the motivation of the Anti-Fascist vote for Westminster (the one that's swept throughout just about every EU country since the referendum).
I think it's too easy to see UK politics now purely through the lens of Brexit if you are passionate about Brexit, but the reality is that most people are just fed up to the back teeth of it and don't care. And this is what hard leavers and hard remainers are most likely to miss because it's not their own mindset.
And that might be the undoing of Farage and any Tory leader who want to go down the No Deal route.
I said before that the Tory Party leadership candidates would be unwise to only talk about Brexit; they need to present much more.