in so far vs to that degree

in so far and to that degree both are adverbs.

Word	Noun	Adjective	Verb	Adverb
in so far	No	No	No	Yes
to that degree	No	No	No	Yes

As adverbs, in so far and to that degree are synonyms defined as:

Other synonyms of in so far include insofar, so far, to that extent.

in so far (adverb)	to that degree (adverb)
to the degree or extent that	to the degree or extent that