Yea, like most parodies, you have to squeeze time a little bit sometimes to fit words in. You see this in hymns and American folk a lot too.

I borrowed a syllable from the original lyric "Singing", which gives you an extra syllable on the last line (making it 9) when it should be 8.

However, you can still squeeze it in when saying "Telegram" fast enough, and keep the rhythm moving. You just divide the note.