FWIW, if the travelers aren't used to driving in the snow, the easiest drive, IMO, will be from Albany, though Burlington would be a decent option. Virtually every other airport option will put you in a position to drive westbound across VT (which has many scenic drives), but will be mountain routes. US 4 from the I89-I91 junction has a lot of mountains (it goes right past Killington ski area) and can get pretty nasty pretty quickly.
Coming up from Albany puts you on I-87, which is decently maintained, then across NY 149 to US4 eastbound. Having done most of these routes in the winter, I can assure you that that's quite a bit easier than a lot of the other options.