Second the call for a full case study -- hard to know what to advise you to do without knowing how big of a gap you will need to fill if your job goes away and what flex there is in the existing budget.
In the interim, if your spouse's side business looks promising, can you spend the next couple of years while still employed throwing your spare time into helping that get established? If that business is truly viable and profitable in a few years, that could give you a really nice safety net/alternative if your job goes away.
Otherwise, I would just advise you to slash everything you can now. You have a decent stash, but it is not enough to sustain you permanently should your job go away, which leaves you vulnerable to needing to chase jobs wherever you can find them -- and what are you going to do with the big house if you can't sell it but all the jobs you need to cover the bills are out of state? (Hint: you will probably do what I did: take the job and move; follow the old housing market downhill; carry double housing costs for a year; and finally get realistic, cut your losses, and take a giant bath on the house.)
Don't be me. You have the giant gift of several years to plan for a job change. Spend that time getting your expenses to the level where you can cover them with a local job, or bringing your spouse's income up to cover the gap. Or both.
