Programming SAMD21 in a 64pin house using Arduino IDE

Hi. I'm doing a IoT project for my company.
And we are considering using the MKR FOX 1200 board as inspiration.

It has the 48pin SAMD21G MCU on it.
However our project might benefit from the increased pins in the SAMD21J version. But how feasible is it to be able to use the Arduino IDE. (we want to use that to make it easier for our programmer)
Like will the included libraries be able to take advance of the additional pins(like Analog pins, UART, and GPIO).

Of is there a smarter way of doing this than I haven't though of. Ideas are surely appreciated.

Thanks.

Morten L. Hedegaard
Developer @ Comadan A/S, Denmark