Tiny 2040 UART Serial Buffer Size Increase

Hi, I am building a small GPS speed device using the Tiny 2040, a GPS module and an LCD display. The GPS module is not reading complete packets because the serial buffer is too small. I believe the buffer size to be 64 bytes, and a typical NMEA packet is about 72 bytes. I am compiling using Arduino, C++ and the earlephilhower code base. Does anyone know how to change the UART serial buffer size? [I tried searching the core code but didn’t spot any buffer size definitions].