Triban 120 GRVL XS frame for 170cm height

I found an upgraded secondhand Triban 120 GRVL bike that looks good but it’s an XS frame. Purely based on the size chart seems an S frame would be “perfect”. But wondering if an XS would work too, if I adjust the seat height and potentially get a slight longer stem?

I want to buy secondhand as I'm just a "beginner" and also just want to get myself a deal. But been struggling to find S frame gravel capable bikes. The person selling the Triban is over an hour away so don’t want to waste either of our time if the frame is totally not suitable.