Dormir a pata ancha
 

"Dormir a pata ancha" is an Argentine colloquial verbal phrase meaning "to sleep profoundly" generally during more time than usual and without any clock alarm, noise or activity disturbing it. Sometimes it overlaps with the more general expression "dormir como un lirón" ("to sleep non-stop; to sleep most of the day, most of the days", because "lirón" is a dormouse).

Are there similar expressions in English? ¿Otras expresiones en el mundo hispano que describan esas formas de dormir?

Last night Britain's Got Talent contestant Jai McDowell -who speaks in a way I can't almost understand- was asked about what was he going to do until the final, and he joked something that sounded to me "Sleep a (w)hoop!". Does a similar phrase exist? Is it related to this thread's subject?

Thank you in advance for any insight on this.

El dicho más común en inglés es to sleep like a log.
Hay otros. A mi me gusta decir to conk out. Ejemplo: He conked out after being dog tired all day.

La palabra whooping es un adjectivo coloquial que signfica mucho.
Me parece que in Inglaterra la palabra cambiaba un poquito, y alli es posible
decir to sleep a whoop.
Whoop tambien significa un sonido parecido a algunos pájaros como
los whooping cranes.

Thank you. Yes, we also use that expression "dormir como un tronco", I suppose as a literal translation from English and because of the very old Spanish expression "estar hecho un tronco" that means to be apoplectic, in comma, or so deeply slept or sedated that it is not easy to wake up the person.

"Conk out", that's a good one :D. We are also hyperbole friends. We say "¡Colapsé!". By the way, I love the expression "to hit the hay".

Sleep a wink. --Maybe?
Sleep like a baby. --Which I have thought was weird. Babies wake up and cry all night or pee and poop in their diapers. :)
I was OUT! --With emphasis on the word out.

And then if they are pretending they are asleep then they are "playing possum." "Are the kids asleep?" "No they are just playing possum so we will go to bed and then they will get back up."

Those are good ones! Thank you.
I wonder, "sleep a wink"? I know "not sleep a wink" (no pegar el ojo -en toda la noche-), but what may the affirmative describe about the sleep?

"Dormir a pata ancha/suelta" indeed! Also a good example of "(dormir) despatarrado": "los encontré en el jardín despatarrados" ["¡Marche un pote de Aqualane para el muchacho!" (Aqualane: a lotion frequently used to treat mild sunburns)]