Going back to Frank's O/P, I don't think the local elections, nor for that matter the upcoming European elections, will tell us anything. My concern is that the Lib Dems have always been the protest vote in mid-term local elections so you can't really read much from the results from last week and translate it to the national stage or Brexit (I have a mate who happened to be ... or at least was ... a Tory counsillor up in Weston Super Mare - he lost by 16 seats. He said that the main feedback he got from his doorstepping was, as he said it, "a plague upon both your houses").
The same can be said about the upcoming EU election: I fully expect the Brexit party will do well, only because they'll be the flag the anti-EU members of the population will congregate to. And this I think is a real probem for the Remain campaign: they don't have a flag to rally around. Farage is as slippery as an eel and he knows what he's doing, while the Remain voters are fragmented.
For me, the upcoming Peterborough by-election will be a better indicator when it comes to Europe: at the last election Labour and the Tories stormed away with the votes (22,950 and 22,363 respectively, with a +12.5 swing to Labour) while the Lib Dems and the Greens were comprehensively beaten (1,597 and 848 respectively, although their negative swings were both less than 1%). Now I'm not saying that the pro-remain parties will ever overturn that result, but if there was a significant swing towards the Lib Dems and they cut the margin between themselves and the two main parties, then that's the point we can stick our heads up and maybe think there's a change afoot.