Hark! 'tis an elfin-storm from faery land, Of haggard seeming, but a boon indeed: Arise—arise! the morning is at hand;— The bloated wassaillers will never heed:— Let us away, my love, with happy speed; There are no ears to hear, or eyes to see,— Drown'd all in Rhenish and the sleepy mead: Awake! arise! my love, and fearless be, For o'er the southern moors I have a home for thee."
Porphyro's still talking, and he's really trying to get Madeline to start moving.
"Now's the perfect time," he says. "Morning's here, there's one heck of a storm raging outside to cover us, and all of your relatives are out cold downstairs after a night of heavy partying."
Two basic things are going to help them get away:
First, there's this magical "elfin-storm," which, even though it looks nasty, is actually going to help them get away undetected.
Second, all of the partiers are laid out drunk downstairs, and so "There are no ears to hear, or eyes to see."
In a poem that concentrates so much on sensory stimuli and the ability or inability–think of Madeline early on, with her "regardless eyes" (64)—to process those stimuli, it seems plausible that the partiers' inability to hear or see isn't just a result of them being drunk and unconscious, but also because the "elfin-storm" has cast its spell upon them.
They could be, just as Madeline was in the opening stanzas, "hoodwink'd with faery fancy; all amort" (70).
And where is he taking her, exactly? Well, apparently he's got a sweet pad just across the moors.