The attached image shows under the kitchen sink and the neighboring compartment, where the washing machine will live.
The isolation valve in the right side of the images goes to an outside tap, this will be hidden behind the washing machine. I wondered if there's a better way this could be arranged so it's more accessible.
My thought is to fit an adapter to the washing machine cold water isolation valve splitting this two ways. Then attach an isolation valve and flexi hose to one of these (the washing machine to the other) and attach this where the current outside isolation valve is. Then cap off the pipe to the left of the current outside isolation valve. This way the outside tap can be isolated from under the kitchen sink.
Alternatively, just pull out the washing machine at the start/end of each winter. Would this be best or is there a simpler solution to the one I've described above?