You have my sympathy too, in reverse - I live in a small village in Bavaria (although DH hasn't lived in this village before we moved here, he comes from another small Bavarian village about 50km away). I have been here 4 years now, and have 3 kids, aged from just gone 6 down to 5 months.
People think that once you've been in a place a few years you are settled and no longer expect/ sympathise with homesickness, but it comes in bouts I find, and I have been feeling a bit sick and tired of the world outside my window, however beautiful, operating all in German/ Bavarian dialect just recently, sick of myself for still struggling with the language, and sick of some the way things work that are just different, even though I know what they are now...
I haven't been to the UK since May 2010 and we have just booked a trip over for June 2012 - people think because it is relatively "near" I could go back often, but as you say it is not in reality that easy or cheap with more than one small child and when there is significant travel from the airport required at one or both ends, and it is realistically necessary to hire a car at the other end or travel by car and ferry rather than plane... My DH also has no interest in travelling to the UK himself and sees it as a waste of annual leave and money, as he says "it costs more than a real holiday" - which is true, getting back to the UK for a week is about double the price of a week in Italy for the family...
I miss the country, the general familiarity of language and culture, shops and products, just people in the street speaking English, not my "family" in the sense of parents and siblings etc, and my friends all live at the other end of the UK to my family, which also makes going back a minefield...
Sorry there is no solution here, just sympathy and fellow feeling - I have found there are lots of expat groups in the nearest big city but it just isn't practical to get to them with the relative ages of the children, timings and travel, so like you I have lots of local acquaintances and am well known in the village I live in, but don't feel I actually have "friends" which were relatively easy to make in the UK, where I could talk without thinking about what I was going to say in advance or being easily misunderstood...
The kids are very settled here and totally at home, this is fantastic of course but when I feel homesick it makes it worse as secretly I feel trapped by their settledness as I feel it would be utterly selfish of me to consider moving before they leave home!!
So just some fellow feeling going out to you in your English village from my German one!