Ahh..one other question about baggage...
The limits for Business and Economy are 30Kg and 20Kg respectively + the 15Kg for WP status. These are all weight limitations as opposed to per piece when flying to the USA.
Is it okay to spread the weight over, say, 4 pieces of checked luggage as I would prefer to lug more pieces than to try and move 2 very heavy bags. For some reason I always pack 1 giant suitcase per person when travelling even though it is a weight limit rather than a piece limit.
We are travelling to France directly after landing at LHR so that involves the underground to ST Pancras, Eurostar to Gare d'Nord then TER to Brive. Therefore we do have to move the luggage off/on several types of transport + have to wait for all bags to show up on the carousel at the airport

. what would be the best method to employ. minimum bags with max weight??