Despite the Premier of Saskatchewan stating that not even a referendum would help Senate reform to move forward there is a way that it could. Senate reform remains hugely popular among Canadians. What needs to be done is to leverage that support for reform and use it to counteract the provinces interests in addressing every issue they have with our constitution. You do this by crafting the referendum question in a particular way:
"Do you support the federal and provincial governments entering into negotiations to amend only the sections of the constitution that deal with the Canadian Senate?"
Premiers are not idiots. If 75% of voters in their province don't want them going off-topic they won't. Abolishment would still be hard to do, as it should, but there would be a real chance to negotiate reform. Requiring 7 provinces representing 50% of the population leaves plenty of wiggle room once the fear of another Meech Lake is removed.