I'm having some trouble understanding the adverb's meaning in the lyrics for the Japanese version of Melodies of Life from FFIX:
消えゆく運命でも
君が生きている限り
いのちはつづく
永遠に
その力の限りどこまでも
わたしが死のうとも
君が生きている限り
いのちはつづく
永遠に
その力の限りどこまでもつづく
I've roughly translated both clauses: "As long as you are alive even with my fate to disappear, life will continue to the best of its ability forever, wherever it goes. As long as you are alive even if I die, life will carry on to the best of its ability forever, lasting to the ends of the earth." The bold parts entail the どこまでも adverb.
My problem is that I've seen mainly translations of sentences where the adverb has a verb come after it, like どこまでもつづく, rather than at the end of a sentence. Also, those translations use the adverb's definitions as is, one example being:
たとえ火の中水の中あなたにならば、どこまでもついていきます。 - I'll follow you, come hell or high water.
Otherwise, it's an interpretation of the adverb.