Mitt Romney has released plans for 14 campaign events between Friday, January 4th (the day after the Iowa caucuses) and Monday, January 7th (the day before the New Hampshire primary). He is not exactly trying to blanket the state -- the events are almost all in the southeastern portion of the state. In fact, if you draw a line from Nashua up to Concord, across to Portsmouth, then down to the Massachusetts border, you've boxed in all 14 events.
His last swing-through, after Christmas, was similarly centered around Manchester, managing to stray west only as far Henniker.
No doubt, this is the area where the population is centered and growing -- although according to some, that area is increasingly Democratic-leaning, and thus proportionately not as predominant in the GOP primary. (New Hampshire as a whole has been lurching quickly to the Democrats the past few years, but my political sources up there disagree about the geographics of that trend, as well as the permanence of it.)
In any event, John McCain has been hitting a wider swath, and today ventured into Grafton and Belknap counties. In the past few days he's been in Dover, Lebanon, Newport, Hancock, and Rye. It's not exactly Coos County, but it's a start. No word yet on McCain's post-Iowa-caucus schedule.