I say no- because less in this case is a suffix- the opposite of hopeful, which is not made of two complete words.
On the other hand, if teaching primary, I would allow my students to identify the two familiar words within hopeless.
Of course, I had a substitute in first grade agree with my friend that "together" was a compound word. I argured and argued that gether
is not a word, but alas, she finally told me to sit down and not worry about it. I've stewed over it for 35 years