I don't know. Most I have cashed is $1,000, and that was done without anybody blinking an idea. Just a routine transaction for them. I use Vimenca, which is one of the biggest in the country. If there is a limit, I would think it would be high. However, you may need to make arrangements in advance if very large to be sure they had enough money on hand at the time you wanted to make the change.
Vimenca has branches in most locations.