45 miles each way?
At 80mi/day, you're facing some serious maintenance requirements for the bike you choose.
I think for the distance you are traveling, the question isn't can you do it on a C5, it's should you. For me, the answer would most definitely be no. I am not an RE owner yet, but I plan to continue using my beater KLR650 to commute. It's already ugly, it gets pretty decent mileage - the difference between the KLR and C5 on a week-to-week basis is pretty negligible - and the general cost to maintain is probably lower than almost any other motorcycle. It also has an obscenely huge aftermarket for things to make the ride a bit more comfortable.
Look at it this way.
KLR (or some other long-lived cheap Jap bike):
C5
- Expensive - relatively speaking, and for what it is
- Slow
- Pretty
I don't see the point in riding a nice bike like the C5 into the ground, in the long run. Personally, I'd rather see over traffic and go head to head with the big bads riding into Philly on something that, past general mechanical soundness, I don't really care about.