Midwest - Minnesotans: when to buy MSP-LHR/LGW?

Good morning folks...

This is a kind of cross post with a similar query in the San Francisco forum. Although I fly between the UK and the USA a few times a year (my fiancé is from northern MN) we need some help pulling things together for our wedding in London. We're getting married on Saturday 1 September 2012, deliberately a few weeks after the Olympics to try and keep travel and accommodation costs down for our American family.

Our closest family members will be coming from MN - near BJI, in fact, but they are happy to drive down to MSP given the possible savings. I have a pretty good idea about when to buy flights from the UK to the USA, but from the USA I'm not so up to speed.

Flights have opened up in the last few weeks for September 2011, and we're looking to book a 10 - 14 day trip ex-MSP (or conceivably ex-BJI if DL has decent faces) to LHR. It should cover the weekend preceding (25/26 August) and the weekend (1/2 September) of the wedding, but precise days are flexible.

The best fare is currently $950 all incl. with Icelandair. But if you were planning a trip from MSP to LHR with those parameters, when would you start looking for the best fares? Like trans-Atlantic flights from the UK, I'd expect them drop a bit before they get more expensive closer to departure.

Thanks for any tips and advice. ^

For a September trip, I usually book in the spring or summer, unless there happens to be an amazing fare sale. Booking too far out usually doesn't get much in terms of price and flexibility. I haven't flown Icelandair, largely because its schedules haven't worked out for me, but I've heard nice things about them. $950 all-in is a reasonable fare for that time of year. These days, I'm lucky to find flights under $1K between MSP and Europe.

Thanks daregale - my fiancé recalls better prices around $700, but we're probably a few years out of date. As long as the folks are happy with the connection in Reykjavik (which I understand is guaranteed, and part of a bank of US / EU connections) it could be the one. We'll probably hold out a bit.

Once upon a time, I was getting $700 fares but they're rare these days, it seems. I'd also watch the direct flights on Delta to see if you can catch a sale.