In my experience, that's not abnormal to get a V8 going. My LS needed to crank once it hit 40º or so outside too. The Town Cars wouldn't crank quite that much, but then the 4.6L modular in those is lower compression and tuned more for comfortable cruising than power vs. the little 4L V8 in the LS.
I would be skeptical of it being a fuel pressure issue. The fuel supply line is usually kept at close to working pressure anyway, and I suspect that if it needs to "top up" pressure it happens as soon as you get the key to the on position.
BTW, on the keeping the line under pressure thing-anyone who has ever opened a fuel line without disabling the pump can attest to this
. When I change a fuel filter, I pull the fuse, start the engine and let it die, and then crank it a few more times to relieve pressure in the fuel line. My dad once had a fuel filter changed at Jiffy Lube(not a good idea) and they re-used one of the old line clips-a few days later it failed and left a nasty mess of gas.