Make sure you take the 301 through Waldorf and Virginia until you get to the I95. Some GPS or other nav systems want you to go up to the beltway and then go around to I95, bad idea at most times.
Our last trip down was not bad. The roads in SC can be rough so be ready to get bounced around. Stop and get fuel in GA just before going into FL, the prices are cheaper and I found it hard to find a station in Jacksonville area.
Have fun. Orlando is worth the trip, especially with kids.
We take I95 from our home base, exit 166 in VA straight through until we get to I4 in FL. Traffic on our trip last August was pretty much non-existant. We made great time both ways. There was construction in GA on 95S from exit 50 or so to exit 29. No delays or anything like that but a very long line of jersey walls so it felt a little tight in places. We use the Flying J at exit 29 for gas before entering FL. Gas in FL was .25 - .35 higher than GA.
95 from Richmond to Daytona Beach (where you'll pick up I-4) is one of the most boring interstates in the nation, with zero scenery (unless you count South of the Border signs as scenery). That said, it's a fine road for traveling and you'll make good time.
2008 42' Foretravel Nimbus CE
2007 Chevy Tahoe toad