BT100, your fiancee is going to HAVE to learn to pack light or you two wont be getting on the plane or into a rental car. I have travelled for years back and forth to europe, first with my parents and then on my own. Here's some ideas:

1. Silver-impregnated socks, t-shirts and undies. They dont smell even if worn for several days in a row. In addition, they can be easily rinsed in a sink and hung to dry over a radiator. Here's a source for the socks: http://www.sockcompany.com/foxrivxstatx.html
My wife and I ended up using just 4 pairs of their x-static based socks for two weeks of travelling. The other main silver stuff is called Visa endurance. Mountain Hardwear uses visa endurance in their undies that fall under the catagory of: "eXtend" wear. Mountain Hardwear has boxers for you and undies for her. Again, just 2-3 pair per person should do the trick. Also, the eXtend series has t-shirts and long underwear type stuff as well.

2. For more formal stuff: ONE pair of nice pants, ONE dress, ONE nice shirt and Doc Martens for shoes ('cause you can even hike in them and then just rinse with a damp towel that night for going out.). All of this clothing should be in wrinkle resistant cloth.

3. The rest of clothing should be stuff like the Mtn hardwear t-shirts and other "hiking" type clothing for generally getting around.

4. You should BOTH be able to fit all your clothing in one medium sized bag. The other medium sized bag should be for goodies to bring home.

5. Look up and book rental cars prior to going. We got a smashing deal from Avis at the Glascow airport: $500 for two weeks! We got a vauxhall corsa and it was PERFECT for all the small roads and such. It's like a geo metro, so plan your packing around a car that size (we just had our bags in the back seat).

6. Goto Sainsburys or other similar grocery stores for lunch items. This will save you mega bucks and you can generally leave things like fruits and carrots in the car without refrigeration while you drive. Also, hard cheeses and salami (in it's casing) can survive for weeks without a frig. We simply bought a cheepo set of plastic knives/forks etc and they worked to cut stuff. No swiss army knife needed.

Hope this helps.....Ozone