Linda, I've just had another of those great ideas
(seriously) - why not invest in one of the mobile internet dongle thingies? Then you could also use it when you're out and about at shows and on campsites. Installation is a doddle - will help you with it no problem.
I know it doesn't solve the actual wireless conundrum, but until that can be solved, the long ethernet wire you've got on order and / or mobile internet could provide a perfect get-out-of-jail clause. Why, it's even a perfectly allowable business expense and at £7.50 or so a month at least it keeps a bit of tax from flowing into revenue's coffers!!!
Laurie (full of bright ideas today!)