to that degree vs insofar

to that degree and insofar both are adverbs.

Word	Noun	Adjective	Verb	Adverb
to that degree	No	No	No	Yes
insofar	No	No	No	Yes

As adverbs, to that degree and insofar are synonyms defined as:

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

to that degree (adverb)	insofar (adverb)
to the degree or extent that	to the degree or extent that