You're doing great. The oil is probably just a seal leaking. I am down in southern Mexico right now and my bike has been seeping for the last 4000 miles since I didn't think to change the oil filter cover O-ring and brought oil filters but no O-ring. I look at it as a feature since the oil blows off the back of the bashplate and oils the chain. Sort of a redneck scottoiler I like to think. Oil is cheap and a few teaspoons is more of a nuisance than anything.
I had good luck with freecampsites.net when traveling in the U.S. down to the border. Public libraries have free wifi if you need a quick check of the weather or a place to camp for free.
It's cold at night in the mountains for camping in Northern Mexico in December. The mountains are a refreshing break from the coastal heat further south. 25 bucks a day means you'll be camping a lot.
I used to get gas in Ukiah on the way out 244 to the Hardy Souls campout out at Lehman Hot Springs in the late fall for a few years when I lived in Oregon.