Recent reports indicate that Canada is slowly but steadily withdrawing from the purchase of F-35 as a replacement for its aging fleet of F-18s. The poor performance and extravagant cost of the F-35 are the reasons.
The F-35 has nothing going for itself instead of a low radar cross section and this is only a minor aspect in overall fighter plane design. Given the advances in sensor technology, radar and infrared, stealth won't really matter much in the future. The F-35 won't be invisible to the enemy. So you are paying a lot of money for a feature you don't need and that offers little advantage.
Canada should first define its requirements and then run a competition. Canada has to protect a huge territory. Therefore, it needs an
affordable long range air superiority fighter.
There are six planes on the market.
F-18 Super Hornet
The cheapest solution would be the F-16 and Grippen, but these are single engine airplanes with limited performance. The F-16 is rather dated and I don't know wether it is still in production. If you don't mind only having a single engine just like the F-35 and want good performance at low cost, then the Saab Grippen should be on your shopping list.
Saab Grippen (single engine / low cost)
However, the extreme weather in the arctic demands a more reliable solution with two engines. Since you probably want to keep on using the American rockets and bombs acquired for the F-18 that excludes the Rafale, unfortunately, since the Rafale is a great plane.
The F-15 strike eagle would offer some advantages over the F-18 in terms of aeronautical performance, but the plane is rather dated and future upgrades are not very likely, since it is being phased out in the US. This leaves you with:
F-18 Super Hornet (price, convenience)
The obvious choice would be the F-18 super hornet, because Canada has been operating this plane for some time. The newest version called "super hornet" does offer a couple of performance improvements. It would definitely be a good choice and a lot better than the F-35.
In terms of fighter performance, i.e. speed, acceleration, agility, climb rate and service ceiling, the Eurofighter Typhoon is by far the best plane on the market. The typhoon beat the F-22 in several mock dog fights earlier this year. BAE and EADS - the prime manufactureres - are struggling to get new contracts since they lost to Rafale in India due to price.
So this is a buyer's market. If Canada employs its negotiating skills effectively, Eurofighter GmbH could offer Canada to become part of the consortium that is producing the plane by letting Bombardier enter the group. Canada will probably want to manufacture parts of the plane and adapt it to its specific needs, for example by developing conformal fuel tanks in order to extend the range of the aircraft. The Brits would be delighted, I am sure.
Finally, whatever Canada choses as new fighter plane, the Saab Grippen, the F-18 Super Hornet or the Eurofighter Typhoon, it will be better than sticking to the F-35.