Grammatically both sentences are correct but confusing with meaning and hardly to be translated correctly.
Rule
If the sentence containing too…to is in the affirmative, the sentence containing so…that will be in the negative.
But for translation it hardly can be translated correctly. It is still vague in how much we try and change. It is similar to ( The news is too good to be true \ The news is so good that cannot be true.
It is likely joking with language or mokering.
There is similar to this language in our culture called ( asteism)
i.e a type of irony
too = adverb ( very )
- The old man is too wise not to follow your advice. = the man is wise enough not to follow ...... ( He is a bit cautious until he is sure of the advice ( So how he takes with advice ) ? Perhaps he will go with that someone's advice when he is sure enough.
- The old man is so wise that he can \ will follow your advice easily.
it carries the same meaning ( he will accept the advice when he becomes sure of it)
Conclusion ( Not good sentences \ confusing )
My suggestion:
I suggest changing both sentences as :
The old man is too wise to follow your advice. ( positive ) = His wisdom helps him to distinguish which advice to follow ( either yes or no)
i.e. according to the context, apparently he does not follow the advice.
The old man is so wise that he cannot follow your advice easily. = both logically and grammatically correct and the meaning is the same.
Finished