This actually came up for me this Spring; I just wasn't smart enough to see the potential.
I was working on meeting the girls in NYC and flight to EWR with a prolonged overnight connection in YYZ staying with them at our condo was cheaper than direct to YYZ. Not to your scale, but cheaper all the same. I remember telling DW it seemed messed up. I managed more away from work time to spend with them in TO, so I flew earlier, surprised my daughter and just let it go.