Boring choice but as above Mondeo Estate. Comfy, relatively efficient on fuel, You can probably fit the shed in the back. Never owned one but they’ve been our works pool cars through various interactions for the last 15 years. People, kit, motorways, site roads, no bother. Just sit back in the velour seats and calmly cruise to wherever.
My longest trip in one to the far side of Germany and back in a week with 3 days on site in the middle. The car just worked, no hassle, no surprises and not burned out on arrival.
Edit: it’ll swallow a bike wheels on. Can probably get a tandem in the boot it’s that big.