Bedding Dahlia

yes they can. lift the plant when it has been blackened by the first frosts. cut foliage down leaving about 2-3" of stem. stand stalk down so sap drains for about a day. I then put in a deep tray of sand/sawdust mix and put in the coalhouse which is frost free. you can put them in dry compost if you prefer.
come spring replant and water as needed.

welocme to goy by the way.

or you could just leave them were they are they will grow next year.

if the tubers are well buried then just leave them as cliffo says but i mulch mine with a thick layer of garden compost.