I think it depends on a lot of factors. If you are crocheting a cap and doing the hair (and you have to teach yourself to crochet), it can take a bit of time
I am going to use the starrysheep tute and sew the hair on this time, which will make things faster for me since I suck at crochet.
I will also recommend if you have never made one before (and esp. if you don't have a waldorf doll at home to compare to), to spring for a "premade inner head."
I used a premade inner head the first go around. This time, I'm doing the inner head myself, and I spent an hour last night just getting it firm enough and in the tubular gauze. I haven't even added the string yet. I think the premade head is worth the money to avoid the trouble. Also, if I didn't have my other doll to compare firmness to, I would have made it far too soft. As it was, I rewound the ball 3 times before I achieved the right firmness. I think it would be almost impossible to know this without something to compare to. I also had my husband there as a reality check when I wanted to pretend I got it right the first (and second) time.
I am feeling confident about the whole project since I already did it once before, but I think (for me personally) if I had to do the inner head last time, I would have done a bad job without the comparison of one that was "right" and also would have been overwhelmed.
Sewing the body and stuffing it/putting the doll together didn't take me too long if I remember right. I think I sewed the pieces and stuffed them in less than 2 hours?? The face takes time to do correctly. And you'll need to do some clothes which will take some time.
but for me, by far the most work went into crocheting a cap and hooking in the hair. I think using the chunky hair and doing the starrysheep tute way of attaching it will go faster. Look at my other thread in this forum to see what I'm talking about ("deconstruct this picture" thread).
I'm like you in that I plan to do an hour a night or so. There's something therapeutic in working with the wool too. I really enjoyed my "struggle" with the inner head last night even though I felt some frustration at times.
I think it is well worth it to do this labor of love. DD loves her doll I made two years ago. It still gets love. I fully expect it to stay in our family for generations. I am so proud of it. I can't WAIT to get this funky little doll made I'm working on now. For me, the most challenging part is managing to work on it in secret after my girl is asleep without getting tired myself!