That's the worry, daytime show ends up rating well! Before you know it we'll see a Homes Under the Hammer there.
Richard Osman recently has the idea of showing highlights of different daytime shows in one primetime programme! Only a joke but what a thought for an early Saturday evening slot
I have the feeling BBC and ITV concentrate their Saturday night effort in the autumn with Strictly vs X Factor and that is it. We do have BGT on ITV soon, but because Ant and Dec's SNT is "rested" for 2019, there is no big live Saturday night appointment to view show this Spring. It feels both channels are saving their effort until September.