We will be travelling in May and think we prefer train to flying (for several reasons) - Can someone please advise travel from London to Colmar? We're going to Mulhouse next, so something in that direction.
I've looked at tickets on RailEurope but figure there might be a better way that we, as foreigners, aren't aware of. Is London to Paris via E'star going to be the first leg regardless? Many thanks!

We did the same journey a couple few years ago. Yes, Eurostar to Paris then Paris to Strasbourg on a very fast train. It was an excellent journey. We did the last bit via car meandering down the wine route

You might be able to get better rates going through the operators' own sites, rather than RailEurope:
www.eurostar.com
www.voyages-sncf.com

Also check www.seat61.com for all sorts of general information and advice.

Change either at Lille Europe or at Paris (according to the train you choose) and in most cases at Strasbourg.
If you leave London at 10.24 or 14.22 you can catch a direct Paris Est - Colmar train.

Thank you all so much for taking time to reply!

Forget Rail Europe - they are middle-man rip-off artists. Use Trainline (same prices as the French National Railway - SNCF - and same schedules). You will want the Eurostar (www.eurostar.com) from London to Paris, then probably the TGV to Strasbourg, then likely a local train to Colmar. Should all be evident on the Trainline website. If you use www.voyages-sncf.com you may have problems with a U.S. credit card. Not so on Trainline.

The cheapest TGV tickets (called PREMs) start selling out 92 days from your date(s) of travel. After that they get progressively more expensive. I think you can buy Eurostar tickets starting 120 days out from your travel date, but others here will know better than I about that.