Almost every expat carries a quiet internal timer labelled someday we will decide, and the deciding is harder than expected because life keeps happening while you postpone it. The factors that actually tip people: children reaching school milestones, aging parents back home, career trajectories in each country, whether permanent residency or citizenship is achievable, property and pension logistics, and the softer question of where you feel most yourself.
A pattern worth knowing: the decision rarely stays made. People commit to two years and stay twenty, or plan forever and leave in three. Life events reopen it each time, and that is normal rather than indecision.
What helps is making the choice deliberate instead of default. Set periodic reviews with your partner, keep options alive in both places by maintaining home country documents and relationships while pursuing residency rights where you are, and be honest about whether the home you miss still exists as you remember it. Return is its own migration, not a rewind.