Hey Max, Do yerself a favor.. Go to a local truck stop and get yerself a current edition of the, Rand McNally, Motor Carriers' Road Atlas (Truckers Atlas).. It has a wealth of knowledge about clearances and road hazards, State by State.
I'm 12.8 tall and have never had a clearance issue. We've been Coast To Coast via All Interstate routes an most US highways.. never had a clearance problem. We have encountered a couple Low Bridge or Low Clearance spots on SOME back east state highways but they've ALL been clearly marked Well ahead of time and Most all have a By-Pass route. The Truckers Atlas will warn you of all of'm.
On your Antenna ? Most are angle adjustable. I angled mine down to about 60*.. No problems then. Better Yet (?), cut the dang thing off'n go XM.. I did.
When we go up the East Coast from Florida to Maine, we like go I-95north to I-26, at Asheville NC, I-181 north to I-81. I-81 all the way to Binghamton NY, then I-88 to Albany. Then US-2 over to I-91, north to US-2 again.. brings you out at Skowhegan Ma, couple more miles and yer in Bangor. As many times as we've done that route.. the Scenery always changes or looks different, some how.
The best, best part is... You do don't have to deal with ANY of the BIG East Coast Cities.
Traffic is Traffic. I run with the trucks, and give way to the trucks. Been There Done That (OTR).. Run with'm not Against'm... makes for a leisurely drive. Actually FUN work'n with'm.. If you know what I mean ?
Just one route. From one RVr thats done it a couple times.