My husband has a business event in London in October. We'll spend a few days there and then want to head somewhere else. I was hoping to get to Ireland, but am afraid it might be too cold/rainy. Maybe Amsterdam? I don't want to spend more than 5 hours traveling from London. Maybe Spain? France is out, as we've been there several times in the last year.
3.5 Hour flight on BA to Budapest. RT about $300 last time I did it. The European discount airlines are even cheaper but I enjoy real service. Another idea is just go the BA website or if you don't mind the discount airlines go to their websites and see where you can get cheap flights. I love Budapest and October is a good time of year to visit, as it is one of the months with the least rainfall and the temperatures are cool but still not cold generally.
How long a trip? It would be easy to find enough to enjoy in Belgium and the Netherlands for a week or so. If you want to fly, it'll be more than 5 hours: an hour to the airport, at least 1.5 hours before the flight, then at least an hour from the airport to your hotel. That's a minimum of 3.5 hours without flight time or traffic delays, probably more if you are checking luggage. But it's not all that much more, and then, as James says, there's all of Europe in front of you.