where I have home to i81. that would be your starting point when you cross the nj/pa state line on i78.
home to i81................... 1 hour 1 min. 71 miles
i81 to ma....................... 1 hour 19 min. 87 miles
ma to wv ..................... 10min. 12 miles
wv to va ...................... 22 min. 25 miles
va to i77 ...................... 3 hours 23 min. 241 miles
i77 to nc ...................... 26 min. 32 miles
nc to charl. nc .............. 1 hour 44 min. 97 miles
char to sc..................... 11 min. 12 miles
sc to i26....................... 1 hour 13 min. 88 miles
i26 to i95...................... 49 min. 53 miles
i95 to ga...................... 1 hour 07 min. 53 miles
ga to fl........................ 1 hour 44min. 111 miles
fl to i4 ......................... 1 hour 42min. 119 miles
i4 to exit 68.................. 54min. 62 miles
now keep in mind, these times include gas stops and rest stops. this is the 16 hour drive. a bit slower pace. time and mile includes exits. entrances etc....
this is a good idea with stops, no sit down meals, how long from point to point.
just remember, there is no perfect way. there could be a crash, traffic any way you go that can hold you up. I also don't use the "belt ways or bypass" I stay on 95 and 4.
the trip I did these times and miles I hit little traffic. I also think I read you were going during the week, being from nj I don't have to tell you what a Friday or Saturday during the summer months can do to traffic on the shore point interstates and 95 in the summer on Friday and Saturday can be fun.
and there again, if you live near i95, leave at the right time and drive straight thru, it can be a quick way of getting there.
I also use 78/81/66/17/95/4 but that's is during the winter months. if your not use to 66/17 and can be a little confusing.
good luck and have a nice trip!