With a long crank, pop the hood and pull then firmly reseat both ends of all ignition wires to see if it's a loose boot clip or bad wire. If it now starts up (or now never starts) then you'll know.

I'm thinking too much fuel, not too little. There have been RWD posts here in recent years with similar symptoms that mentioned leaking injectors could cause both fuel rail pressure loss and initial flooding making for a long hard cold start then running normal after initial rough running coughing out the fuel. Any initial black/grey smoke out the tailpipe when it finally catches? Check fuel rail pressure when left overnight vs.right after running. Pull and read all plugs after a failed long crank to see if any are wet or fouled notably different. If you've got a cold start injector then add that to the equation.

One low tech approach would be a couple of tanks of super premium with mostly high revving long trips through the mountains (aka an Italian tuneup), maybe even add some rxtra injector cleaner like Techron. If that makes a notable diff for a few weeks of cold starting then that would suggest fouled injectors and/or plugs are involved.
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Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now