Good advice on the surface, but as someone who works in the industry, I have to warn you that pretending to be with a corporate account you really have no affiliation with is a dangerous proposition. I'd strongly recommend against that course of action. You may find the LDW voided and your rate jacked up if you are unable to prove you work with that company. It may not happen, but I would suggest it's not worth the risk.

If you're worried about driving in winter conditions, the $20 per day for LDW (and perhaps purchasing liability, too) is most assuredly worth the extra cost.

Honestly, though, driving in winter conditions isn't terribly hard. Just remember the three rules: slow down, brake early, and leave yourself a margin of error. It's not worth not renting a car over. You'll be too limited in what you can do in Fairbanks without one, anyway. With a car, too, you won't need to depend on a tour company to take you to where you can see the lights--all you need to do is drive 15 miles outside of town in any direction (though north, like on the Elliott or Steese highways past Fox, would probably get you away from civilization and into the darkness to where the lights would be most spectacular). In fact, you'll likely see them in the city itself (if they're bright enough), but to make the experience even more awesome, getting away from city lights is key. This page recommends either atop Ester Dome or in the Chatanika area (mmm...eat at the Old FE Gold Camp, although I think Chef Alexander is no longer there), this one suggests the same and links to a couple of tour operators, and this UAF professor suggests a few additional spots (here, too).

Anyone know what the deal with the ice hotel at Chena Hot Springs is this year? Is it going to go up? That might be a cool place to view the Northern Lights from...