Any recommendations for family friendly hotels to break up a journey in Spain or somewhere online to book something a bit more interesting?

try looking at Spanish paradors. These are government maintained buildings but usually set in castles etc. there are some real stunning locations.

Not spanish, but there are 47 Ibis hotels in Spain

Hotel Campanile have some hotels in Spain. Clicky
They’re decent enough if you just want to sleep somewhere then move on early the next day. When in Spain we’ve tended to use Booking.com. Never had any issues and got some surprisingly good deals.

Whereabouts in Spain are you looking for a hotel?

We want to spend a few days exploring the Pyrenees and Costa Brava on the way back from/to Barcelona from the Roussillon.

Ibis is big in spain. You will find good deals with out breakfast.

I stayed i village hostals in the pyrenees, only c 35e per night. Look on the portals and contact them direct to book, they need the money and at 35e or so they dont make much.