OP here. Thanks to everyone for your thoughtful responses.
Can you go ahead and complete the transition to the unrelated freelance work? Do you just feel a responsibility not to leave them since they don't have a replacement plan?
Sure, I could go ahead and move on and focus on just my freelance work. I feel a small responsibility to them as I've been there a long time and like the people I work with. However, that is only a minor point. The bigger issue really is fear of completely pulling the plug. What I do is becoming somewhat obsolete and once I leave, there's likely no going back to this field (not that I want to, but a potential concern if I needed money). If anyone can point me to threads on fear of pulling the plug, I could use some advice in that area. :) I'm FI but of course a little more money always sounds better. I'm fully aware that I have a moving goalpost for my FI number. I'm actually deeply entrenched in OMY.
You said you negotiate to work 20 hours and keep full time pay. Do you mean you kept the full time hourly pay, or that actual total salary? If the later, that is a really, really sweet deal!
Yes, it's the total full-time salary. I'm not a high earner (mid to high five figures), but it's still a sweet deal. It's made me question if I'm being unreasonable to expect that they'd continue to pay me this rate for 20 hours. I've been mulling this over, back and forth, and I just don't know what is reasonable or not.
It almost sounds like they're trying to make you an offer that you can refuse because they want you to leave. Or they want to draw you into some sort of negotiation where they lowball you in hopes that you'll negotiate to a slightly less-offensive wage and schedule. Either way, I'd leave and pursue another job if you really want to pad your stache. It sounds like your management team is incompetent, cheap, conniving or all of the above.
I'm not sure what you do for work, but I have a hard time believing an individual can get a meaningful amount of work done in only 10 hours in a 40+ hour work week. There's no way I'd re-arrange my schedule 4-5 days a week to work 10 hours.
Really good points, thanks. They have told me they'd like me to stay. If they didn't, they could have just let the current contract lapse at the end of this month.
About drawing me into a lowball negotiation, I think this could be what's happening. Hard to say. What I do isn't rocket science, but it's esoteric enough that it's difficult to hire for and takes a good while to really train. I just found myself in a spot of good timing where the other person who did this same work left end of last year and was not replaced, leaving me as the only one there who knows how to do the work. There is a new employee who's been training with me most of this year, but it's not that person's full-time job and it's something that takes a good couple years to really get up to speed on. This person is in no position to be able to do all of this work themselves, but I don't know if managment fully understands that. I think they do to some degree.
Thanks again, everyone, for your insights. I do appreciate it!