Heat pumps, per se, almost never use that much juice...
The killer is that it is as common as dust for them to have FIELD INSTALLED resistance heater boosters, one or two.
If the climate is somewhat mild only one strip will be slipped in.
As you go north, expect to find two resistance heaters.
Neither of them will be listed on the outside label, which will only show the basic heat pump demands.
So until you open the box up and inspect for the boosters you don't know what you've got.
Personally I've never seen a heat pump without boosters.
The boosters ( for cold, cold days ) are electric pigs and will typically require multiples of the base demand.
If your HP needs, say, 20 amps then its first booster would lift that to 40+20=60 amps.
The only time boosters get omitted is if the climate never reaches freezing. Never.