Feel a little bit better about the Ekos poll after reading Kady O'Malley's breakdown of the two weeks of numbers. Week one just before the G20 and through its end plus a few days (June 22-29) had the Cons at 30.6, Libs at 26.2. It's the next week, June 30-July 6, that sees a swing where the Con lead goes to 34.4 to Libs at 23.9. Whether this is the Queen's visit and its halo rubbing off on the Conservatives or a G20 effect, I'm sure everyone has their own opinions. No other party's national numbers really seem to be moving, thus the focus here on the Cons and Libs.
Notably, the numbers in Ontario offer quite a swing too, over those two weeks which you can read at the above (second) link.
Not great kids but at least the two week look gives it a bit of perspective and suggests some volatility.