Hi there Imclaff, We have the square type that zip together, bought from Argos, Towsure have them and Barrons Caravans have them at different weights for thickness and warmth. You can buy from Towsure on line, they are quite good.
All else fails and its cold use a couple of fleecy blankets as well as sleeping bags.
Warmest option is to just get two good mummy bags, but make sure you get one with a left hand zip and the other with a right hand zip, then just zip them together.
Any decent outdoor shop should sell LH and RH zipped bags.
Most envelope type sleeping bags will zip together to make a double. We just use a pair of cheapo's zipped together with a summer duvet over us inside the bags. Warm as toast.
After much research, I have just bought 2 Coleman summer weight mummy type bags from sales at puffinproducts.co.uk. They are£14.99 each + postage. They offer a free sleeping board to keep out the damp if camping.
If you buy 2, they send a left & a right zipped bag so they can be joined together. Quite roomy (my husband is 6'4'') and very cosy.
This is a new firm just setting up. Very pleasant to deal with and delivery is by return pf post.
We have the same as Shirley. think it has a zip down each side. We bought ours from a Yeoman's exhibition and I think it was cheaper than Outdoor Gear too. Was very successful in France last year.
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.