Honestly, Tim Hortons needs to go back to the basics- which should not have been this difficult if not for corporate incompetence.
Two most important points:
1. Fix the coffee. It's horrible, and Macdonalds has already snatched up the original supplier- find another one that matches the original as best as possible. Coffee is king in grab-and-go retail.
2. Know your market. Tim Hortons will never be upscale; people with money will always end up going to Starbucks or the fancy local coffee store. Sales are still stable-ish for now because of the same long-timers that have gone to Tim Hortons for ages- there's no guarantee that a more discerning younger generation will stay with Tim Hortons in the future. It should emphasize being both fast and salt-of-the-earth local (true in many smaller communities where the Tim Hortons is the community fixture).
Other things to get back to the public's good side:
3. KISS. Keep the menu simple. No more Impossible whatevers, no fried chicken sandwiches, no overly fancy drinks that require their own machines to make.
4. At least 1/2 of the baked goods (simple things) should be made in-store. More complex baked products like glazed donuts, etc. can still be made in a central factory.
5. Fix the meals - less salt, slightly larger portions. The sandwiches are bland and awfully small; the soups are way too salty.
6. Ad campaign touting a 'Back to the basics' Tim Hortons, focusing on nostalgia (most people still remember when Tim Hortons was good)
7. Start implementing self-serve kiosks and focusing on app orders to help speed throughput in grab-and-go locations. In sit-down locations, retain a locally-hired cashier.
8. Don't focus too much on foreign expansion when the homeland is stagnating. In foreign countries, localize to a degree- successful foreign brands like Macdonalds do this in countries like France or China.
9. Bring back the bread bowls. Chili bread bowls were the best!