Extending a visa, exiting the country, and returning

[ajwhite]

I'm a US citizen visiting Canada for 6 months and am looking to extend my visit to stay with my significant other for another 6 months. During this time of extension, if it is granted, am I allowed to leave the country and return on my extension? Or once I leave, am I no longer covered by the extension?

Thanks!

 

[scylla]

Leaving cancels your extension.