Marco was born and raised in the Tron, and his folks are from Chile, which has climate esp in the south, not that different from NZ or parts of Europe. Plenty of towns & cities with cold/wet winters. Desert/arid in the north though.
It's just that a lack of sunlight means less Seratonin (the happy hormone) wherever you live, and can therefore exacerbate any general unhappiness.
I'd be a bit more curious to know Rojas's off field family situation. I note Wood, Reid & Thomas are all coupled up, or married. Last 2 with kids. Plays a big part I reckon to settling in overseas. A single Thomas coming back from a 12 month knee construction, might have thrown it all in and returned to NZ, without a partner and child at home to brighten him up daily. Tyler Boyd has the big guy upstairs.