Quilts are an alternative to sleeping bags, here are some examples

Therm-a-rest Blanket

I use a therm a rest duvet. Worth every penny

Zenbivy Quilts

Have a look at Zenbivy , they do a synthetic quilt . They are based in US but they do have a UK distributor in Bristol . I have a Down quilt from them and the fast sheet and their super comfy mattress .I cannot recommend them highly enough and quilts as an alternative to sleeping bags .I used my Zenbivy this summer on a long distance trek of 84 nights and never once was I too hot or too cold