As soon as you get into Britain, head northwest until you reach the mountains. Follow the edge of the mountains around the north until you get to a dungeon on the edge of a lake. In front of the entrance is a large blue rug with eight chairs attached to it.

This is a flying carpet. If you double-click on one of the chairs, everyone will get on it and it will lift up. You can go nearly anywhere with this -- across the ocean, over mountains, wherever. The only problem is that it won't land in a spot that doesn't have enough clear space.

Once you have the carpet, find/make/steal some barrels and stick them on the back of the carpet. I think four or five will fit there. This will give you room to haul all the extra stuff you'll need and not encumber your party. (This rug must be VERY strong to carry eight grown men, a barrel full of gold, another full of beef jerky, etc.!)