There are, as you've seen, a couple of different ways to skin this cat. In some ways, it depends on where
in Florida you're ultimately heading. But lets assume you will be crossing the border into the Sunshine State at Jacksonville.
The trick is, once you're south of the Virginia/NC border, there are literally NO issues with I-95. South Carolina is a little bumpy, but it's three lanes in both directions all the way through Georgia, so you can get from Emporia, VA to Jax in about 9 hours without even breaking a sweat.
The western route using I-81 is nice, much more 'scenic', and longer. It also MAY, repeat MAY be an issue weather-wise in late October, but probably not.
Coming down from NB, you want to avoid everything between Hartford CT and Fredericksburg, VA.
I hear there are smoothness issues with the interstates up around Albany, Binghampton, Allentown and such. However, you will not find I-95 or the Cross Bronx Expressway any better, trust me.
I would stay west of the metropolis for as long as you can - and then, as noted, when you are past Washington DC/Richmond, you can then get on I-95 and just cruise the rest of the way.
With your rig, you definitely
do not want to mess with the George Washington Bridge, the northern stretches of the NJ Turnpike near Newark, or I-95 between Baltimore and DC, if you are not used to driving in that kind of traffic.