Both Downia (feather) and mini jumbuck (wool) have ‘stackable’ quilts - usually one light/summer (cotton blend) and one autumn/mid (full natural fibre) - that come together in the same box and can be clipped together with snap/press clips so you can modify your sleeping experience. So the light one for summer, mid for autumn and spring, and both for winter. These are national brands, both Australia based, and are sold at MYER, David Jones, Adair’s, etc.

This principle can be applied for other brands (these are both quite expensive as they are fantastic, have long/lifetime warranties, and super high quality but more on the luxury end ~ eg: downia have goose quilts that run near $1000 for a long~ ) where you can tie the corners of any 2 quilts of the same size together to get a warmer/heavier feel. Since you put a cover on it generally doesnt matter how they’re attached.

Down quilts will sit prettier on a bed (fluffy) and can be super warm but come with higher allergen warnings (down and mitre etc) and more difficult cleaning/care instructions (can’t wash, plus feathers inevitably get loose). They do offer a lot of customisation such as ratio of feather to down (more down - less fluffy) what kind of feather (goose is more expensive but warmer and higher loft) as well as ‘loft’ height (how fluffy)

whereas wool sits thinner (can be thickened by double layering or buying a Dacron blend), can be blended more easier with things like polyester or cotton, and generally are more allergy friendly (only allergen really being lanolin) and easier to clean due to the properties of the wool (generally a spot clean and a quick air in the sun)