I remember the good old days of power banks and carrying multiple banks around CES just to keep powered up. These days, something like the UGREEN Nexode Retractable Series Power Bank 20000mAh 165W ...

There are smaller high-capacity laptop power banks available, but the Anker Prime 27650mAh is a respectable mixture of power and portability—and is particularly well suited to the 16-inch MacBook Pro ...