I can't figure out why that would be the case. For directional satellite antennas, sure, you can only point them so low to the horizon, so if you're trying to aim at a geostationary satellite the further away from it's regular footprint you go, the worse it will work. But GPS doesn't work like that, the satellites are in medium earth orbit and cover the globe pretty evenly. GPS receiver antennas are typically either omnidirectional or are optimized for receiving signals from straight overhead.

As long as you aren't dependent on the terrestrial data network for maps, a cellphone GPS should work quite nicely anywhere on the globe. Now, with that said, I have no GPS experience outside of North America, so if there's something going on that I don't understand please let me know.