sjjohnson1938 - that is why I wasn't worried about the extra cost as I had figured it was about a break even, but didn't do detail calculations. Plus, to me it's about the experience not the cost. If I was worried about a couple hundred here or there on teh trip, I wouldn't be going this far anyhow.
By the way, your calculations were off as you didn't taken into consideration over 1/2 the time was in Canada even staying in the US longer.
So fuel actually cost more taking the longer US route.
1> Caclulation is good
2> 567 miles in US @ $3/gal plus 1354 - 567 = 787 miles @ 4/gal
567 / 15 * 3 + 787 / 15 * 4 = 113 + 210 = $343
So the shorter distance is actually saving $48 plus 4hrs drive time.
Like I said in the OP, wasn't worried about the cost, but was wondering how the roads and camping availability for this alternate route.
Though not mentioned, I already know I'm not crossing directly at North Portal but a different, limited hour, small backroad crossing in the general area. Just used North Portal as the reference because it was a bigger crossing and easily to tell the route.