Yeah I'd be swapping the tank out and taking the Gu if you have it. Or keep an eye out over the next 12 months for another LR tank for the Gu.
When I did the Madigan Line I was going to swap out the LRA tank from the GQ but picked up another second hand tank from a GQ for $350 a month before the trip and now have a Long Range tank in both cars! Awesome.