Yeah I posted a similar article about Trump campaigning in some democrat states. It is really stupid and will be extremely expensive. I'm guessing he is thinking that some of the Republican donors will help fund all this stuff, but I doubt they help somewhat. I guarantee that RNC and/or Trumps campaign will be extremely close to being broke as they will have to help Trump campaign in Democrat strongholds, protect other states that use to vote Republican but is now could be competitive( because of Trump), defend seats, and attack Democrats. I also think he doesn't even have offices in some battleground states yet.
He doesn't have the money yet to do ads. But'll have to do some ads eventually I think, because he can't be everywhere at once. The main problem I bet Trump has is very little surrogates. A Obama, Hillary, Bill, Joe, and possibly Bernie team( plus superpacs) will all go against Trump and the Republicans, and some Republicans won't help Trump even if they verbally support him. I think that is why Trump wants to unify the party. He won't stand a chance against an onslaught like that and some Republicans won't lift a finger to support him in practical ways.