Ooooooooh, now you have me thinking! We're a big vacationing family too.
Here are two ideas for you for FAMILY trips.
Driving: Do "the big drive" Out West. I know it's a heck of a long way from Maryland.....it was a heck of a long way for us from Detroit! The alternative is, you could fly to Rapid City, SD and then drive from there. We did this 2 summers ago and the kids loved it and learned SO MUCH. I think it's important for kids to see just how big our country truly is and what an obstacle the prairies were for the Pioneers. Look at a map and trace I-90 out of Chicago.....up across Wisconsin, Minnesota, into South Dakota. My kids adored the Badlands in South Dakota....also the Missile Silo near there that can be toured. There are Lakota Indian sights near Chamberlain SD (along the Missouri River) as well as Lewis & Clark sights. If you have Little House on the Prairie fans, those are also in SD (Minnesota too, maybe?). Near the Badlands you can also see historic sod houses. Amazing!
Close by is the Black Hills of South Dakota which is a family wonderland of Mt. Rushmore, Custer State Park, spectacularly scenic family hiking, caves, wooly mammoth bone sites, more fossils than you can believe, horseback riding, wildlife wildlife wildlife.....you name it. The whole place has a very "wild west" feel to it. Google "Black Hills Travel & Tourism" and you will get a wealth of information.
If you want to stray further west in your travels, you can visit Devil's Monument, Oregon Trail sites (swing south and west into Wyoming) and Custer, Wyoming and Grand Tetons National Park and Yellowstone (all a solid day's drive west).
FLYING: Costa del Sol in Spain. This was recommended to us by another Tugger family (Sydney) and was a dead-on recommendation. It is an easy trade in the winter months. We went in February and had a great time and had very pleasant weather (right around 70 in the day). For a February break, you would have your choice of condos to trade into. We traded our 2 bedroom for a huge gorgeous 3 bedroom in Estepona. If you're considering this, find the Rick Steve's Spain guidebook and look it over for ideas. In a week there we visited Granada and the Al-Hambra, the Rock of Gibraltar, the Pueblos Blancos of Spain (Ronda was close by and spectacular!), more Moorish castles than we could count, caves caves and more caves with cave paintings (wow!) and Neanderthal skeletons, wonderfully picturesque towns, a day trip to Morocco, a visit to the southernmost town in Europe (Tarifa)....I could go on and on.