I've had a few 1 night stopovers in Doha. I find that Discover Qatar has similar prices to the QR website, but less flexibility in choosing (you can't choose a different fare). Nowadays I book the flights and stopover hotels separately. I found that long layovers price normally, but they are under 24 hours. I've even had a 23h45m layover (and booked the hotel separately.) This was searching for round trip flights, not multi city.