Broadly speaking, the short answer is no: a northern elite would not think of a plantation owner as an equal.

But before I go into more detail, I need to make it clear that my background is in American literature. I cannot answer this question from the perspective of an historian proper, but rather I can point to how conceptions of the South — in particular here, the plantation owner — developed and how this relationship was navigated by Northerners.

From pre-Revolution through the Civil War and into Reconstruction, the North saw itself as the source of cultural and intellectual production for the country. Even prior to the country's independence, the South was an important ideological construct for the development of the rest of the nation. It was a kind of internal 'Other' that the rest of the country could point to and localise the nation's moral failings therein in a form of therapeutic castigation.

The most glaring phenomenon in the US was obviously the institution of slavery. If America is exceptional, if it is the country where the ideal of Republicanism is made manifest — how does that square with the spectre of slave labour? But as long as this was thought of as something particular to the South, this national identity crisis could in some ways be accounted for.

So how did the plantation owner become Southern as opposed to American? The origins go back to at least as early as the mid-18th century. As an example, a French-American author named Crevecoueur produced an epistolary semi-autobiographical account of his travels in the British colonies of America wherein he repeatedly distinguishes 'the dismal latitudes' of the southern plantations from the North. Charleston, SC is there imagined as the tropical foil against the Old World-inspired North, which Farmer James identifies as the new source of republican virtue. (Letters from an American Farmer) We see here in Crevecoueuer and elsewhere how the South is imbued with European notions of the New World: tropical, fertile, a place to be colonised, farmed, and tamed.

For Crevecoueuer as well as many subsequent authors, the civic-minded Farmer is the literary embodiment of the American everyman (or think of Thoreau, writing nearly a century later). The Farmer finds his doeppelganger in the Planter: if the Farmer is industrious, self-made, and in possession of those well-known and praised American traits, the Planter embodies concentrated wealth, abjection, and slothfulness.

Consider Royall Tyler's posthumous novel The Algerine Captive (one of the earliest American novels), which seeks to capture the manners of New England. The protagonist Updike Underhill is given full relief only after he receives a letter from a caricature of a Southern planter. Underhill cannot understand this fellow's manner of speech. He is at once aristocratic and deprived, imperial and barbaric. For Tyler, the Planter-class embodies the contradictions that define the nation in general.

Here's another writer's account of staying with an anononyous southern planter:

The Gentleman of fortune rises about nine o clock. He perhaps may take an exertion to walk as far as his tables to see his horses. Which are seldom more than fifty yards from his house… He then lies down on a pallet on the floor, in the coldest room in the house, in his shirt and trowsers only, with a negro at his head, and another at his feet to fan him, and keep off the flies. Between twelve and one, he takes a drought of bomobo, or toddy, a liquor composed of water, sugar, rum and nutmeg, which is made weak, and kept cool. He dines between two and three… At dinner, he drinks cyder, toddy, punch, port, claret, or Madeira, which is generally excellent. Having drank some few glasses of wine after dinner, he returns to his pallat, with his two blacks to fan him, and continues to drink toddy or sangaree all the afternoon… Between nine and ten in the evening, het eats a light supper of milk and fruit, or wine, sugar, and fruit, and almost immediately retires to bed, for the night…furnished with musketoe curtains…

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This answers your second question: the decadent slothful plantation owner was a trope before the Civl War.

The larger takeaway here is that, prior to the Civil War, the plantation owner embodies all the pernicious and troublesome qualities that underscore the foundation of America herself. So no, a well-to-do northerner would look down on a Southerner and view him either as some antiquated relic that harkens to the yolk of colonial rule, or as an immoral man who's wealth is predicated upon the unethical institution of slavery.

Jennifer Greeson explores all of this in much greater detail in Our South, and it's the best account of how the South is represented in literature and culture in the first half of the US's history.

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