Final answer:
The notwithstanding clause has seen limited but significant use outside of Québec, such as by Saskatchewan and Alberta, and was almost used by Ontario.
Step-by-step explanation:
Regarding the use of the notwithstanding clause outside of Québec, there have been instances, though less frequently than in Québec itself. The notwithstanding clause, section 33 of the Canadian Charter of Rights and Freedoms, allows provincial or federal authorities to temporarily override certain sections of the Charter.
As for significant use, while Québec has invoked the clause on several occasions, other provinces have used it sparingly. For example, Saskatchewan used the clause in 2017 to protect school funding practices. Alberta also passed legislation including the clause in 2000 concerning definitions of marriage, though it was rendered moot when the federal definition changed. Ontario's government threatened to use it in 2018 during a dispute over the size of Toronto City Council, but it wasn't ultimately used as the legislation passed after a court appeal.
In conclusion, while Québec has made more frequent use of the notwithstanding clause, it has seen limited but significant use elsewhere in Canada.