What are the comparative/superlative forms of the adjective "well," meaning "in good health"?

Solution 1:

You're asking for specific input on "well" as an adjective. My feedback is that while you might find "weller" or "more well" in usage, and also the superlative "wellest" as well, I have personally never encountered this in conversation or regular usage, and you're better off using the other common expressions (e.g. he's in great shape, he's excellent, his health has improved exceptionally well). It's probably because "to be doing well" is not a strong expression in itself, but very context dependent. Even when intended to emphasize a positive outcome, it's almost a euphemism (e.g. Bezos is doing really well in his personal finances), or it's used to compare to a previous "unwell" situation where the contrast is stark. If you want to amp it up I suggest you use adverbs "really, exceptionally, very".

The answer to the 'fill in the blank' will not satisfy you, since 99.999% of natural English speakers would opt to say "I feel a lot better today..." rather than insisting on using "well" as a base adjective.