I just wish my PC would wake from sleep as reliably. I'm lucky if I can get it back up after one night, never mind five months.
Wow. Just for reference, an 8.2 meter ground telescope (the Subaru in Hawaii) was able to capture objects at a magnitude of 27.7 after staring in the same spot for 10 hours. 
 April 10, 2017: Nap Time for New Horizons: NASA Spacecraft Enters Hibernation [ http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20... ]
 New Horizons News Archive [ http://pluto.jhuapl.edu/News-Center/News-Archives.php ]
I did find this article  from when New Horizons was going to Pluto and if the reason is the same, then the hibernation is to prolong the life of the instruments: New Horizons spends much of deep cruise in hibernation - essentially long stretches of electronic slumber in which many of the spacecraft's subsystems (such as science instruments, navigational star trackers and most flight electronics) are turned off to extend their life, and the craft is spin-stabilized to minimize thruster usage.
 New Horizons Spacecraft to Collect More Data When "Hibernating" [ http://www.spaceref.com/news/viewsr.html?pid=41333 ]
So one good reason for it to hibernate is to save thruster fuel.
That said, there's a whole lot of nothing out there. It makes sense to put the craft into a safer mode that has less risk of failure when there's nothing for it to do.
I really have no idea what advances might enable that, though.
What instrument do you watch? The cameras are more like telescopes with very narrow fields of view. Slewing the spacecraft around aimlessly snapping pictures isn't doing science.
Next, space is big and empty. Many people have visions of dodging asteroids, planets, comets, and moons, but you only encounter these things when you aim for them. A typical journey across the solar system would encounter nothing larger than a grain of sand.