Looking to get a new sleeping back this week but head is spinning on what to go for. Have saved up my pocket money to about £450 and looking for a bag that I can more or less use all year. Looking at the PHD Hispar 400 and Mountain Equipment Lightline SL. Currently using a Zero rated bag from Decathalon and Alpkit inflatable mat. Spent a fairly uncomfortable night in Glencoe last weekend with the tent covered in light frost. Even had my down jacket on in bag and was feeling the cold. Maybe its an age thing,. Really need a better mat as well. Seem to suffer from sore hips and a lot of tossing and turning. Wonder if it is the cold coming through the mat affecting my hips more than anything. Any advice on a good multi season bag for a cold sleeper would be appreciated.