Today, are there people living in the backwoods of Louisiana who can only speak Cajun French?

There are some interesting stats on this page:

Exiled from their native homeland of Nova Scotia in 1755, the Acadians wandered aimlessly along the Atlantic seaboard for years before settling in the rich fertile soils of south Louisiana. The 6,000 Acadians who refused to swear allegiance to the British crown were punished for their disloyalty with destruction of their homes and expulsion from their homeland.

This horrendous voyage marked 30 years of hardship and humiliation for a proud group of people. At each location of disembarking along the Atlantic Coast, these refugees were welcomed by open hostility. Through the generosity of the Spanish Government, Charles III, they were transported to south Louisiana where they settled on friendly land. Here, they established small farms along the swamp and prairie region of the Mississippi River, Bayou Teche, Bayou Lafourche and other locations in the southern part of the state. For almost 200 years they remained in isolation because of inaccessibility to this region. Even under Spanish rule, a large majority of the colonists continued to speak French.

A distinct culture and a dialect known as "Cajun" French was born. Cajun French began in Nova Scotia between 1604 and 1756 and traveled to Louisiana where it matured and further developed. It is the only modern North American language and has undergone many linguistic changes over the years.

www.lafayettetravel.com/culture/language

Sorry for the shouting but this is the way I received the message.
Message from and thanks to LELAND AND SALLY CROCHET

THANK YOU FOR THE QUESTION, THIER ARE HOMES WHERE CAJUN FRENCH IS STILL SPOKEN. OF COURSE WE HAVE NO BACK WOODS BECAUSE THE CAJUN COMMUNITIES ARE LOCATED ON THE COAST WHERE WE MOSTLY MARSH AND SWAMPS, THE CAJUN COMMUNITIES EXIST FROM NEW ORLEANS LA, WEST TO THE TEXAS BORDER ALONG THE COAST NEAR THE GULF OF MEXICO.
MY WIFE AND I ALSO SPEAK CAJUN FRENCH,WE HAD TO SPEAK FRENCH ,OUR FATHER , MOTHER AND GRAND PARENTS COULD NOT SPEAK ENGLISH.

LOG ON TO OUR WEBSITE, www.crochethouse.com SCROLL DOWN ON THE LEFT TO RAJUN CAJUN RADIO FROM 6 AM TO 10 AM OUR TIME, YOU MAY LISTEN TO CAJUN EVERYMORNING.

THANKS A BUNCH

SIMPLE CAJUNDS

And another message from Louisana:

'Hello my name is Jo Ann. The answer to your question is yes.'