Have you ever considered a down quilt? They are quite expensive but ideal for motorcycle travel.
If you have a decent bed that insulates you from the floor the part of the sleeping bag that is underneath you just compresses and adds little or no warmth. I have a simond down bag that has a centre zip and I only ever lay it over me and never get inside it, just put my feet in the foot box and most quilts come with a foot box. In hindsight I would have bought a quilt as the pack size is tiny. I always go for down as the weight/size to warmth ratio always seems better.
If you have a decent bed that insulates you from the floor the part of the sleeping bag that is underneath you just compresses and adds little or no warmth. I have a simond down bag that has a centre zip and I only ever lay it over me and never get inside it, just put my feet in the foot box and most quilts come with a foot box. In hindsight I would have bought a quilt as the pack size is tiny. I always go for down as the weight/size to warmth ratio always seems better.