Adverb (fukushi), Noun
how much; how many
Usually written using kana alone
アメリカの尻馬に乗るなというセリフに正面から反論するのが、どれほどしんどいことだったことか。Just how tiresome was it to argue straight against the phrase "Don't blindly follow America's lead!" no matter how (much); however
Usually written using kana aloneas どれほど...ても/でも, etc.
(not) many; (not) much; almost (none); hardly; barely
Usually written using kana aloneas どれほども, with neg. verb
Also written 何程【どれほど】、何れ程【どれほど】