If you leave DE at 4:00 on a Friday morning you should be fine.
On I-95 from DC southbound, weekday afternoons are crowded, but Friday afternoons are extra crowded. The difference on Friday is that I always see plenty of additional out-of-state plates from NJ, DE, NY, PA, along with other northeast states and often Ontario too. I assume that many people decide to get a head start on their vacation and decide to leave on Friday - however many forget to plan ahead (like you are, so congrats) and leave home normal morning or mid-morning and end up joining me and thousands of my friends on 95 right around rush hour (which on Fridays is pretty much anything between noon and 8:00). So if you leave early enough to pass through before noon you may find a slight delay but not major. The slowdown is generally anywhere from MM170 in Springfield to MM126 in Fredericksburg, and once south of there it's fine until you get to Richmond, and always always always take I-295 around Richmond (more travel lanes and higher speed limit) instead of staying on I-95 through Richmond.
And on the way home, the same people who pass through here on Friday afternoons tend to all try to get home on Sunday afternoon and evening - and I-95 northbound tends to get really backed up between MM118 in Thornburg up to MM140 in Stafford, then has good and bad spots up to the beltway in DC. For those continuing north to DE, NJ, and similar, if you leave I-295 going around Richmond and take US-301 north it will take you more toward a eastern route and will make for a much more scenic and pleasurable drive than watching brake lights for a few hours.
Enjoy your trip!
Also, here's a handy site to know what's located at a given exit on I-95...
https://www.i95exitguide.com/