Just popping this up for any others looking to do the Picos Europa and Googling.
The Cabana Veronica proved uncontactable in advance and is not bookable anyway. It is wardened by a nice affable chap whos main role is to communicate with the Guarda when there are emergencies. We went prepared to bivvy, but a blizzard (mid June!!) forced us to request a bed. At first the warden was a bit dour, but when he realised we were mostly well equiped, knew how to read a map, and were planning some interesting stuff he warmed up a lot. We slept together on a shelf, and the warden insisted on having the door open. It was minus 5 outside and the snow was blowing in. We didn't have ice axe and crampons so the route to Urriello Refuge was a no no the next day.
Before the end of June there is no need to book huts (except for maybe the popular Urriello Refuge) as its pretty quiet. An ice axe is a must before July if you want to do any peaks, and crampons are a defo before the end of May. June is a bit of a weird month, check out the Fuente de El Cable web cam
https://www.cantur.com/instalaciones/webcam/5-teleferico-de-fuente-de/param... and if there is significant snow on the background peaks pack for winter conditions. September is the quietest and most stable weather wise we were constantly told.
Most of the huts can now be booked on the internet and all (except the Cabana Veronica) have duvets - you need a sheet sleeping bag. The Refugio Terenosa has a facebook page and is not far from the road head above Sotres:
https://www.google.co.uk/maps/place/43%C2%B013'55.5%22N+4%C2%B046'... You can park here. We found hitching really easy up the hill from just below Sotres.
Two keywords on the map:
COLLADO (and similar variants) - A pass you cross on both sides even if there is no path shown on the map. e.g. the Collada Labrada between the Picos Arenizas and the Pico Teserero.
HORCADO - a one sided pass with a tricky scramble on the other where ropes are probably required. e.g. Horcados Rojos has a roped descent. Note. There is a Collado west of the Horcados Rojos and on the west side of the Urielles Penas - this can be taken to avoid the roped descent if snow is covering the rope, taking steep scree around the South or West of the Jou de Los Boches.
There is also a low level route from the Cabana Veronica to the Collado Jermoso hut not marked on the map. See map here:
http://www.foropicos.net/fotos/c/CASARES-JERMOSO.jpg Red spots on the rock mark the route (occasionally!)
Its cheaper to take a hire car from the airport than the bus (and quicker). The 1:50k map is rubbish, the new 1:25k map is much better.