Looking on the internet deeply has found these results:

that would be fine is the most popular phrase on the web.

that will be fine 110,400,000 results on the web	that would be fine 13,020,000,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
Yes, yes, that will be fine. Because that will be fine. No, I'm sure that will be fine. The champagne, that will be fine. Listen. I promise you that will be fine. I think that will be fine. Yes, please proceed with the way you do things, that will be fine. That will be fine, thank you.	Yes, that would be fine. And that would be fine, if that was all of the information. Now if I were training you for a career in radio, that would be fine. And I feel like if we were a niche band, then we'd have our little thing now and that would be fine. And that would be fine, because I would have known my soul mate, my one true love. Yes, I think that would be fine. If this standard were to be applied worldwide, that would be fine: everyone would thus be in the same boat. And that would be fine, if that was all of the information.

that will be fine

110,400,000 results on the web

that would be fine

13,020,000,000 results on the web

More popular!

Yes, that would be fine.
And that would be fine, if that was all of the information.
Now if I were training you for a career in radio, that would be fine.
And I feel like if we were a niche band, then we'd have our little thing now and that would be fine.
And that would be fine, because I would have known my soul mate, my one true love.
Yes, I think that would be fine.
If this standard were to be applied worldwide, that would be fine: everyone would thus be in the same boat.
And that would be fine, if that was all of the information.