I think you need to sit down with this guy and have a serious talk.
You say you're together for convenience, have children, you own the home so it's not his in any way, he commutes an hour, and he's a great guy, but you're not madly in love with him.
To tell the truth a lot of couples are like this. Mutual respect and caring are what makes a relationship work in the long term. I think you have a wonderful basis for a long healthy relationship.
If he's willing to just let you guys go away what are his long term plans? What about child support? Visitation? Getting the kids back and forth to and from visitation, how many months of the year will he have them? Will he have his own place with bedrooms for the kids year round?
These are things to think on for sure.
As for you, you have a career, you make a lot of money at your current job and it's about to be gone. It's nice they let you know. My hubby was working in a great job and life was really good. Money could go into savings and we had enough to buy our needs, some wants, and have some left over.
We had just bought cars that year and our car payments were over $700 per month. Our car insurance alone was over $1100 every 6 months, full coverage. It was really really hard to give up our new cars when he got laid off 6 months later. If we had known he was going to lose his job in a few months we probably would have bought much less expensive cars without all the bells and whistles or we might have just made do with the one we had then just got a program car for hubby.
Having 90 days to make a plan is a really nice thing. It gives you time to make a plan.
I do think you should discuss the option of moving nearer to his work. It's fair to him to give that a try. If you can't find a job in the area you are in then moving to his area would be my next choice. Then if that doesn't work out you could look in surrounding areas that you can commute to also. Even if it's the opposite way from his work. Being in the middle gives you a whole circle of places to choose to look.
You're about an hour from San Francisco. Are there job possibilities there for you? Could you commute with another person in your area to work a job there?
Child care is such a minimal cost compared to moving. Then expecting your family to help, those are not costs that would make any difference to me because the kids being able to have their dad would be more important.
In a couple of years both kids will be in school all day and child care will go down drastically to just before and after school care. Having free child care over the next couple of years....is it worth moving the kids away from dad and having to deal with visitation schedules, plane fare, travel expenses of getting them to him for visits, then doing without them for possibly the whole summer or Christmas break?
These are long term things of course, if you really want to move home and deal with all that goes with moving kids away from their father plus the emotional turmoil they'll go through for losing daily interaction with dad then it's worth it.
On the other hand you're at a crossroads. What do you want to do with the rest of your life? Work just any old job that makes a living or find a job in your field that pays well or a regular job that utilizes your skills but isn't the greatest job in the world...it's a dilemma.
You have the means to move anywhere you want. You could even find work overseas. The world is open to you. You don't need money is savings right now for the kids college, you truthfully have 15 years to save money for that. Use the money from the sale of everything you own except clothes and a few select pieces. Then you can pack up and go anywhere for as long as you want.
What an opportunity you have!
I still think that having to deal with the logistics of visitation and stuff with dad would be the main issue to determine the choices you may be okay with all that. Being without the kids for extended amounts of time so they can go visit dad and his family is something I'd have to take into consideration above all else. So I'd probably stay together and be content with finding work in the area. Living together with someone who is a good person that I respect and have feelings for it way up there in my list of needed things.