This is intended to supplement the other answers here; you should also
read them if you've not done so already.
There are basically two possible situations when it comes to address
mapping and interaction with the cartridge.
If you assert G̅A̅M̅E̅ and do not assert E̅X̅R̅O̅M̅, there's only one
address mapping configuration possible because ...
The largest ROM space the Atari 2600 could address was 4K. But a number of bank switching schemes (and some fiendishly clever ways to do it cheaply!), allowed carts up to 32K. Although really there's no limit, you can always amend the bankswitching to allow more.
This applies to all consoles, and computers. With bankswitching, possible with all ROM-based ...
If you examine the cartridges produced during the active life of 8-bit computers, then first of all you need to look at the Japanese and MSX. One-, two-, three-megabit cartridges with mappers were produced in rather large editions - in general, the picture was similar to the one that Sega had for the Master System.
Megabit ROM Cartridges
As Raffzahn points out, because memory can be bank-switched in
the address space available to cartridges, the maximum size is limited
only by the intersection between the technology available and how
expensive and physically large you're willing to make the cartridge,
and how you're willing to power it.
Nonetheless, you're probably thinking of cartridges of ...