On this planet, there is a nomadic tribe of humans who are the descendants of unwilling colonists from thousands of years prior. They are a nomadic tribe because of the incredibly extreme seasons, this forces them to cross frozen over oceans and travel vast distances in temperatures that are frigid for four years out of five (note that this planet's orbit takes five years to complete).
Something to note about this planet is that it is a captured rogue world that has a retrograde, oval-shaped orbit. Complex life reclaimed the surface thanks to the brief warming period that benefits this planet. I want to know how a small (around 100 people) stone-age level society could navigate this world. Mainly determining cardinal directions on this planet.