That might be rather more difficult than you might expect. Advent of Code uses quite a lot of 64-bit numbers. A bit of googling tells me C64 BASIC only supports 16-bit integers and 32-bit floats. I imagine the other BASICs have similar limitations.
I did 2023 Advent of Code with my own compiler and this was the biggest challenge I ran into. I only had 32-bit integers at the time so I had to manually implement 64-bit math and number formatting within the language to be able to do the puzzles. You would probably have to do the same in BASIC.
Commodore BASIC, derived from Microsoft's 6502 BASIC, actually has 40-bit floats, with a 32-bit mantissa and 8-bit exponent, not that it would help much, if any, with 64-bit maths.
There are Microsoft BASICs that have 64-bit floats, such as built into ROM on the TRS-80 Model I, III and 4 w/Level 2 BASIC, TRS-80 Model 100/102, TI-99/4(a), Apple III, and MSX systems, or on cartridge such as Microsoft BASIC for the Atari 8-bit computers.