Stuck

At this writing, my flight partner and I are stuck in Wilmington, NC and I just awoke from a power nap on the terminal's couch.
We took off earlier today from Manassas and soon got into IMC for pretty much the entire route. The first hour of the trip was fine and I closely monitored the OAT and the wings so that ice wouldn't sneak on us. Then Peter told me the plane felt weird and sluggish and that he had to pitch up to maintain altitude. Our airspeed dropped about 40kts and we began troubleshooting. No ice on the wings.
"Carb ice," Peter wondered.
I agreed and we engaged the carb heat, which soon returned our airspeed to normal.
That, however, wasn't the end of the excitement.As we journeyed on south, I began to notice slight accumulation of rime ice. With just a dusting on the leading edge, I filed a PIREP (pilot report) with ATC and Peter and I decided to keep a close eye on the situation while remaining at our altitude for now. A pilot in our vicinity reported breaking out on top at 10,000 feet, 2,000 feet above us so that was a possible escape route. We also knew that ceilings below were at about 4,000 feet.

Ah ha! Dispatch just called. Our wait is over (at 8:15 p.m.) so this shall be continued later...