We just signed up for this tour and want to fly to London first for a few days . Then take the train to Paris. Any suggestions of the best day to fly to London? I was thinking Sept 4 since we arrive in London Sept 5 with the time change. Or maybe another day earlier? Thanks for any suggestions.
What do you want to do in London? I'd pick the flight day based on how much time you have and what activities you want to do, allowing for jet lag day on arrival. Arriving Sept. 5 gives you two full days in London - if that's enough then go for it.
I personally would go to Paris the day before your tour starts just in case you have travel drama (it happens) and to do things in Paris that your tour does not do. Buy your Eurostar tickets early (they get more expensive as travel dates get closer). Also consider booking multi city flights (in to London, back from Paris) to avoid backtracking.