Both the Liberals and Bernier have a lot of to be concerned about in the by-election results, although the front-runners cut as expected in all three cases. For the Liberals, the early days of the SNC scandal has certainly taken it's toll: an increase of support since the last election on the island of Montreal in the Outremont race (as expected - that's SNC country), but a very much diminished second place polling in Burnaby South and York-Simcoe.
Likewise, Bernier wasn't able to break the low single digits in Montreal (no surprise), but more importantly in a very Conservative riding in suburban Ontario.
Of course by-elections don't mean very much by themselves, except in relation to what the various parties were trying to do: in Burnaby South, the Liberals and Conservatives were keeping their powder dry to prevent Singh from losing and being replaced by someone more effective as NDP leader. That left the field open for Bernier to try to make a demonstration of momentum and the best he could manage was 10%. Likewise, the Conservatives weren't trying at all in Outremont but still handily out-polled Bernier. And the Liberals very much wanted to be able to show support in a Conservative Ontario riding and came up short.
My read is that Bernier is a spent force expect as a spoiler in Quebec, the NDP has nowhere to go but up, the Conservatives are looking healthy, and the Liberals are stronger in Quebec but hurting everywhere else.