In reply to Chmusar:
I made the move to a quilt last summer. I made a plain quilt and then modified it three times, based on experience.
If you buy one really wide, say 1.5m at the head end, then you will not suffer from draughts and you won't need straps to hold it in place. But it will be just as bulky as a sleeping bag.
If you buy one that is only 1.0m wide, it will move with you, so you will suffer badly from draughts. The benefit of less bulk is not worth the loss of effectiveness.
I've ended up designing a quilt 1.2m wide but adding flaps, that go under the mat, to prevent draughts. That works just fine down to 8 degs C but I suspect that in winter, you will need more width.