The only way by road into the Moine Peninsula would be along the A836 up through the centre of Sutherland. You'd probably need to upgrade the entire length of road to be able to accommodate heavy loads and take out any tight turns. Possibly more practical would be to build a port in Loch Eriboll and ship absolutely everything in. The expense, in either case, would be eye-watering. In short that BBC article is one long on imagination and short on everything else.
The route to the Highlands site is an A-road in name only - it's one way for most of the route. The nearest train station is about 15 miles away.
The route to the Shetlands site is a prop plane or a ferry and then a decent drive on fairly minor roads including another ferry.