"Should I bum around North America for five months taking pictures on someone else's dime?"
are you fucking kidding me
1) have at least two bodies. This gives you two lenses to work with quickly and gives you a fallback if one fails.
2) Have more lenses than you think you need. At a minimum, a decent macro, a tilt-shift, a list of primes and a long-throw zoom.
3) If you're not using lightroom now, start. You're about to be swimming in data and if you can't move quickly and get shit canned you will drown. Shoot tethered on the job if you can.
4) A decent manfrotto tripod (a real one) and a decent gorillapod or two.
5) A couple flashes that can be triggered remotely.
Buy all this shit. use parents' credit cards if you have to. Your window is too steep for a long-term rental. Take everything out of boxes, get decent cases for all of it, and put the boxes somewhere safe. You're going to relist it all on eBay when you're done and you'll take maybe a 20% hit, maybe 30%.
Get a CAA/AAA card. You're going to want to never have to worry about breaking down.
See if you need a work permit to be doing commercial photography in the US for 5 months. If you do, try and get one. If you don't, come up with a cover story.
If you have any sort of agenda, you can fly your boyfriend to you. 5 months is manageable. The trick is to spend to see people. Just because your car is in Michigan doesn't mean you can't fly to Montreal for a weekend.
I might even get a shitty little voice recorder or whatever to take memos as you drive. Because you're going to find the most interesting ways to get where you need to go and you're going to take pictures whenever you see something interesting and you're going to caption your photos every night and you're going to transcribe your notes because fuckin'A, girl, someone is paying you a pretty sum to go be a travel journalist. I don't think Conde Nast pays that well. Even if you end up with shit at the end of it you'll have learned basically how to do travel journalism on someone else's dime.