While work permits would be hard to get (In the UK, they are almost impossible, as I remember), it will be of no importance. Unless you are in a major venue or commanding high fees, the US could care less. Folk is, pretty much, off their radar.
At the Philadelphia Folk Festival, we have booked acts from outside the US but they were, usually, well known and well advertised. House concerts, as a rule, are not reported in the Entertainment section.
There is, at least, one house concert series in the DC area. I did a house concert, there, when my CD, first, came out. The man, in charge, is Chance Shiver, and a very nice man, is he. DC is a good area for folk venues, not as good as Philly, but not bad.

                      Mike