I've seen it vary widely. I would say on average, 20-30ft in my personal experience. It explains it pretty well in the owners manual about what all can influence the range; weather, nearby interference, etc.
You shouldn't have to be within arms reach. If so, have your dealer check it out.
Just like vette says though, I rarely ever use remote un/locking. I almost exclusively use passive entry.
I am having range problems with my 2018 keyfob, most of the times I have to lock/unlock the car by pressing the button in the key as the car wont detect it, sometimes even if i am inside the car with the keyfob, the car throws an error "Electronic key not detected" or something like that, Ill have to take it to the dealership.
I remember when the 2010s came out they had a similar issue. The car left me stranded once and wouldn't start. They issued a software update about 6 months into the year that took care of it for good. With the 2018s have mostly new tech I would expect a few early visits to the dealer but I'm sure you'll be very happy in a few months once all this is ironed out