Your scenario is a little more restricting than mine would be, sure. But I see two ways I could handle it.
The first way is to move. Buy a 130k house in Charlotte, NC (that's where I live). Spend 10k on moving expenses. Sell a bunch of crap you don't need that might not fit in your new house, make back 5k.
You now have 365k in the bank. You can either rent out your first house or put it on the market. Spend 25k fixing it up (give or take), you have 340k left.
Get less expensive insurance. 1300/month is way too much; 500 should cover you and the kids. You're not working so you don't need daycare. If you rented your house out, congratulations! Put your remaining 300k in a conservative investment account, generate 20-30k per year in interest, and use that along with your rental income for a fairly stress free (financially) life. If you decide to sell the first house instead, it's a little trickier, and you may have to get a job. That would also require daycare, but you would not have to spend 1k/month on it. Budget that for 500/month. Now even if you didn't get a job you'll still be able to live well for 5 years minimum until your house sells, and if it sells sooner then you're golden.
The other option is to stay where you are and pay off the house. This is the worse option IMO, because you end up not as secure, but it's doable. In that case, pay off your house and you're left with 140k after the funeral (I forgot to include that in Scenario 1's calculations, my bad). Cut costs on daycare and insurance in accordance with your area, get a full time job, and bam, you have 150k in the bank to invest, or for college funds, or what have you. You no longer have a mortgage payment, so your job will easily cover any expenses you might incur.