My top 5 things that come to mind, which are really impossible to do cost/time effectively in one trip:
- Cape Spear / Signal Hill w/ pub stops on Water/George Streets
- Dawson City
- Niagara Falls
- Montreal F1 Weekend (haven't done that yet, - in June out of criteria, but you'd need more than July to do my list properly)
- July 1st Blue Jays game if not doing it at Niagara Falls or in Ottawa