I think that's extremely reasonable. I'd love to have MMR or another form of PR but sadly we do not have that. It's extremely reasonable to vote strategically to keep the CPC out of power. I live in BC and my district is competitive for the LPC and NDP so I'm sure as fuck not voting LPC... but if I were in the interior I'd definitely vote for whoever had more momentum to beat the CPC candidate.
On that note... this is a time to make your voice heard advocating for voting reform to make sure the CPC never threaten a national victory without seriously reforming their platform.