While he'd probably do better than Campbell, the Tory leadership in 1993 is a poisoned chalice. The antipathy the country had towards Mulroney was remarkable and almost unprecedented, the country was in an economic recession, and the Liberal party was well-funded and had prepared very well for the election campaign, where they consistently outcampaigned the Tories.
Plus, after two majority governments, the theme of "change" was very easy to make resonate with voters, and finally Reform was eating into PC support out West (something a Red Tory Quebecois leader like Charest is definitely not going to help). Charest would probably avoid a total PC collapse in Quebec, but he isn't going to hold the whole province against Bouchard and the BQ either, so no salvation there.
Making a better Tory campaign (and it's important to remember that Campbell gave a huge polling boost to the Tories by virtue of being a fresh face and the first female PM - Charest wouldn't get that boost either, even if his overall campaign is less disastrous) is not going to change all that.
It might be a less one-sided blowout, and that would have more interesting knock-on effects for the future of the Progressive Conservatives, but I don't think any conceivable Tory leader is going to prevent a Liberal majority government in 1993. Hatred of Mulroney, fatigue with the Tories in power, and Reform and the Bloc eating into both their western and eastern power bases doomed them - the fact Chretien ran an excellent campaign (something this POD won't change) is just icing on the cake.
There are some interesting knock-on effects, though. Campbell's political life might not be at an end as a lot of people would consider her a huge "what-if" due to her personal popularity. She could (especially if she doesn't lose her seat in 1993) parlay that into another run at federal leadership, or she could return to BC politics. Charest, meanwhile, is basically done after a disastrous loss - leaving a huge gap in Quebec provincial politics. No idea who'd end up taking his place.
Quebec not becoming a monolithic, well, Bloc might butterfly a lot of how the next few elections go. And if the Tories manage to hold on to at least 40 seats, they'll be seen as a far more viable party going forward. They'll still likely end up merging with Reform (the conservative vote in Canada simply isn't big enough to be split between two parties), but the resulting merger is likely to both be perceived as a continuation of (and have a lot more elements from) the Progressive Conservative party.
That probably means no Stephen Harper - quite possibly Peter Mackay ends up on top, though it's hard to say if he'd prove to be as good a campaigner as Harper. On the plus side, there'd almost certainly be less reliance on personal attack ads in the future. I'd say Mackay probably ends up as PM due to self-inflicted wounds from the Liberals, but isn't going to be nearly as successful at it. I'd say Martin wins another majority in 2004, but due to the general unfairness of how that election was called, Mackay hangs on and becomes PM in 2009, probably with a minority, which sets up for a 2011 election against Dion, Rae or Ignatieff. My guess is Rae, because Dion (much as I like him) was a product of very fortuitous circumstance, and Ignatieff was a horrible campaigner. With a Liberal party that wasn't looking for a saviour/Trudeau replacement, and against perceived weaker opposition, they'd be less hesitant to go for Rae, who continuously gained on Ignatieff during the OTL leadership campaign but never could shake the "Ontario hates him" hesitation.
How 2011 would go depends entirely on how good a campaigner and minority leader Mackay is. He could absolutely rout the Liberals if they're still weak in Quebec and he can play on Ontario's fears of Rae, but if he's been seen as a bumbling PM or doesn't run a decent campaign, the Libs are likely to get in with a minority. Lots of possible butterflies by that point, though.
