Thank you for all of the replies. I kept the details vague because I wanted to focus on the general thought process. I do agree about the commute being much more problematic for a part-time job. It would be only 4 days/week, but it definitely cuts into the income.
Some more details, to answer some questions:
Stash about $400k. (Edit: checked a few things, right around $500k all in.) Still owe about $50k on house. Not sure how much my DH has saved in addition to this, but < $50k. We are both 44-46 yo.
This is a LCOLA, so the pay we're talking about is about $20k for 1/2 time work, or $50-60k for full time.
I have 2 young children in elementary school. Part of the perfect hours involves minimizing after school care for them. With the FT job, they would have to be in before and after school care, making for a very long day for a 6 and 8 year old, plus adding much more to that expense during the school year. Plus, if there are any issues with travel conditions, it would be problematic having both parents working so far away.
I am not a high energy person and tend to get insomnia. The long days could make me absolutely miserable.
The full-time job is something I've done for a very long time, and I am so over the industry and job duties, though this potential new job would have much more varied responsibilities, which would be nice. The part-time option just sounds like an easy change, and could possibly come with discounts for services that I'm very interested in.
I do like the idea of really adding to the stash and funding college, vs., just skating by like we have been these last 4 years while I've been a SAHM and taking care of my mother.
I would also like live in a bigger and nicer house for a couple decades. It may sound shallow, but I have had a love of architecture and homes since childhood. We could still do that with the PT job, but would probably not be RE in that case. At this point, my DH doesn't feel comfortable RE unless we get to $2M anyway.
I know what makes more sense on paper, but worry that it may make me want to stab my eye out with a fork or something. Plus, the PT job is something I could see doing in a partial retirement sort of way. Not sure if that would be fair to my DH, though, as I'm not terribly domestic in regards to holding up the homefront.