Having read George Orwell's 1942 essay Looking Back on the Spanish War (tip of the hat to @Randal'Thor), it's quite difficult to imagine that Orwell ever came to the conclusion that Spain would be better off under Franco. This is because:
- Orwell continually bashed Fascism, both in practice and principle.
- Orwell repeatedly spoke well of the Socialist cause, even though he was very critical of Stalin's approach to the Spanish civil war.
- Orwell specifically stated that the war was worth fighting even if it was a lost cause.
Orwell in his essay specifically calls out the evil of Fascism numerous times, e.g.,
There is little question that what one may roughly call the ‘whites’ commit far more and worse atrocities than the ‘reds’.
The Reds and Whites of course refer to the left (Communists) and the right (Fascists), respectively. Orwell goes on to describe those who support Fascism (emphasis added throughout):
When one thinks of all the people who support or have supported Fascism... they are all people with something to lose, or people who long for a hierarchical society and dread the prospect of a world of free and equal human beings.
He reiterates this in his description of what was at stake and who stood to benefit:
The hatred which the Spanish Republic excited in millionaires, dukes, cardinals, play-boys, Blimps, and what-not would in itself be enough to show one how the land lay. In essence it was a class war. If it had been won, the cause of the common people everywhere would have been strengthened. It was lost, and the dividend-drawers all over the world rubbed their hands. That was the real issue; all else was froth on its surface.
Orwell's disdain for the Fascists here is clear.
In a number of passages, Orwell speaks highly of the Socialist cause:
What are the workers struggling for? Simply for the decent life which they are more and more aware is now technically possible.
And in reference to his encounter with a rural Italian soldier fighting for the left:
When I remember — oh, how vividly! — his shabby uniform and fierce, pathetic, innocent face, the complex side-issues of the war seem to fade away and I see clearly that there was at any rate no doubt as to who was in the right. In spite of power politics and journalistic lying, the central issue of the war was the attempt of people like this to win the decent life which they knew to be their birthright.
In each passage, Orwell's clear support of Socialism is stated in the context of how its purpose is to provide the masses with a decent standard of living.
Though Orwell supports Socialism in principle, he does not spare criticism for the confounding behavior of Russia, which worked to suppress a revolution in Spain while also doing little to support those fighting the Fascists.
As to the Russians, their motives in the Spanish war are completely inscrutable... their actions are most easily explained if one assumes that they were acting on several contradictory motives. I believe that in the future we shall come to feel that Stalin's foreign policy, instead of being so diabolically clever as it is claimed to be, has been merely opportunistic and stupid.
With that in mind, Orwell's disdain for the left applies to its political strategies and not its desired ends.
In Support of the Lost Cause
Orwell states that evil must be fought and cannot be relied upon to collapse on its own.
Nourished for hundreds of years on a literature in which Right invariably triumphs in the last chapter, we believe half-instinctively that evil always defeats itself in the long run. Pacifism, for instance, is founded largely on this belief. Don't resist evil, and it will somehow destroy itself. But why should it? What evidence is there that it does? And what instance is there of a modern industrialized state collapsing unless conquered from the outside by military force?
Note also that Orwell refers to Fascism simply as the noun evil. It's hard to imagine him acquiescing to evil, even if the cost is death.
Finally, he makes the clearest recapitulation of his support for the leftist fight in Spain:
Whether it was right, as all left-wingers in other countries undoubtedly did, to encourage the Spaniards to go on fighting when they could not win is a question hard to answer. I myself think it was right, because I believe that it is better even from the point of view of survival to fight and be conquered than to surrender without fighting.
There is substantial evidence to think that by 1942 -- five years after escaping Spain -- Orwell had sufficient time to reflect on whether the leftist fight against Fascism was worth it. He knew that Fascism was evil, he felt that Socialism was not, and he knew that evil had to be confronted. He must have decided that the Spanish civil war was worth the fight for the left.