US carriers: the daily-pass treadmill
Verizon TravelPass and the AT&T International Day Pass both sit around USD 12 per day in Portugal (check your carrier for current pricing), billed each day your phone uses the network. T-Mobile is the exception: many plans include international data at no extra daily fee, but at reduced speeds that struggle with maps and photos, with high-speed passes sold on top. Either way, the meter or the throttle is always on.