Not near enough for me to be able to offer specific advice but you could either arrange with friends nearby beforehand to go to their houses, or just abide by the Pumpkin Rule ie if there is a lit pumpkin on display, the house is trick-or-treater friendly.
every year my friends and i hold a halloween party for our kids, we always have lots of fun.
i lived in a few countries growing up and everywhere really celebrated halloween, it was great fun as a kid. i was so surprised when i came to England and on my first trick or treating night (after a good hour of making myself look scary) i got one fun size chocolate bar, got ignored or shouted at or "no thank you" - door shut!
so i guess its not really celebrated here which is a shame.
maybe in smaller communities around the country it is but i have always been in London.
what about checking out your local netmums.com and put up a notice on their noticeboard.