Empty plot over the winter - to cover or not

Straw works well for us, but it does let a lot of slugs overwinter. We have quite a few hedgehogs that help out thank heavens.

I have a thing against dahlias. They are pretty and all that but I love a mix of wildflowers or a random bed. Its because my bil is super obsessive with them. Do you ever show Scarlett? He even bought his car by measuring for boot height for shows. He has 2 huge polytunnels, and 2 greenhouses full of Dahlias, and spends a huge amount of time getting them perfect. He even manages to successfully use hot boxes to heat one greenhouse. I have just begrudgingly let hubby grow some here, as worry he'll become just as obsessed