Rock on, lady!
You guys are in very good shape. Congratulate yourselves. Your asset classes look good to me, from a distance.
5-year plan, eh? We had our first kid when we were 38. #2 at 40. (Sweated the amnio, we did.) Did a lot of travel, ate at a lot of restaurants, went to a lot of parties first. Now we just travel and eat out a lot.
Foreign lands? Me too. Try a little constructive escape reading. Escapeartist, People's Guide to Mexico, whatsupmaz, Loney Planet's Thorn Tree, South America for Visitors, Mexico Connect's Forums (gotta pay--but good value). Hit the library for travel books--Lonely Planet, Footprint, Arthur Frommers, etc. Buy travel books at the book store. Buy Budget Travel magazine. I am into South America, but my wife likes Italy. It is all good background for a real trip.
One secret is that you can work overseas today. Chile is hot right now (

). Native English-speaking engineers? Teach English to Chilean engineers. Chile is a NAFTA country. E-Z for 'Merican engineers to get work there.
How about Canada? (Many of them could benefit from English lessons, but I mean, work there--here, that is; I am in Alberta--as an engineer.) Try Quebec/Montreal. (Remember, I am a globe-trotting engineer-contractor. Definitely a corrupting influence. 8) I am doing my best to lure my old buddies away to come and take jobs away from Canadians.

) Go to workopolis.com
I understand there are two of you, so maybe you can't jump ship right now. Plan vacations!
Warning on self-employed businesses. Engineers' minds run in tracks. It is damned hard to be a self-employed engineer. I am a successful independent contractor, which is pretty good for the average schlub, but I am twice your age with experience you can't buy today. I live out of a suitcase. Tough on family. Better to own a couple of duplexes or fix up and flip houses.
I have looked for alternative jobs for years, but have never found anything that pays as well for a minimum of effort as working as an engineer for someone else. A cynical friend says, "You just have to show up and they pay you!" He has a carpentry shop on the side and he works very hard on his day job, in spite of his jokes.
Forget restaurants. An old and dear friend, another road-warrior, told me once, "Engineering is the most fun a man [apologies, ma'am] can have--if he can afford it." (Immigrant, BS from Purdue, MS from MIT.) This old bud once owned two restaurants. Had a good run, but eventually they went under and he is still digging out from the debt. And he knew the business. A fellow I know back home has a successful family enterprise restaurant. When interviewed in the local paper and asked, what would you tell a friend who wanted to go into the restaruant business? he replied that he would knock him to the ground and kick him until he came to his senses.
Suggest you hang around this watering hole. Some of these guys/ladies really know their stuff. Some of us don't. See if you can tell the difference.
Cheers,
Ed The Gypsy