Should I get a full desk mat?

Yes, go for a desk-sized mat — think 90x40 cm or bigger if your desk allows it. A tiny mousepad won’t cut it with an ultrawide monitor and multiple mice because your mouse needs to travel that distance and a full mat gives each mouse its own lane without crowding. It also protects your desk, looks clean, and lets you slide your keyboard on top. Just measure your desk space first and buy something thick enough to not wrinkle.