Isnt starting when it gets below 35 degrees

Question
When was the last time you changed or cleaned the spark plugs. I had an older car and just would not fire up when it was real cold outside. We ran down two batteries so at zero degrees Fahrenheit I changed the spark plugs. No problem after that
also is your carburetor set up so the choke is working properly?

will need more information, how strong is the battery? have you remover the air cleaner, to check air flow, to run you have to have oxygen fuel and spark, all in the proper portions, Winter temps can often cause paper air cleaners to absorb moisture, then freezing temps, block airflow. what type of fuel system, efi, or carb throttle body are we talking about? Carb or throttle body you can introduce a few drops of fuel in the top (caution do not use much a teaspoon or so from a small open container as vapor is explosive!

check the distributor for cracks. lightly spray it with water. see if the issue reoccurs.

What is engine size? Use a gage and check proper fuel pressure. My info says 41--47 psi, 5.7L engine.
Can you park on level ground to do testing? Visually check for spark at the plugs. Can you check if system is running rich or lean? How long since overall tune-up?

White smoke could be as simple as condensation in exhaust from sitting overnight. I'd be more concerned if white smoke continued when warmed up. The "miss" could be a bunch of things... When was last "healthy" tune up? Plugs, wires, ALL filters including fuel filter? I would start there, makes a good "ground zero" reference point and see if miss is still evident. You might also consider running a good fuel system cleaner w/next tank full of gas. Especially in winter months when temps fluctuate, condensation forms in tank. (water) Spark plugs & water don't get along well.

This is because the spark plugs are fouled out have the spark plugs replaced and make sure they are winter plugs some cars have colder plugs for the summer which have a hard time in the winter.

if you have a no spark scenario i would check your crank sensor located at the top left side of the harmonic balance pulley.the crankshaft (about 11'oclock) a 2 wire plug with a sensor on it check to see if it is damaged or unsecured. this sensor can cause no spark if not working correctly. This sensor is based of frequency not voltage testing is difficult, just make sure that there isnt too muck air gap. and that it is secured.Lastly may want to check timing possible that the belt has jumped some teeth and she has fallen out of timing. maybe a bad tensioner The coil will adapt i think up to 10 degree, ****** or advance. Good luck

change the spark plugs,after they sit in cold and you warm them up to 45 degrees or whatever and you try to start the car the spark is just hot enough to ruin them,especially if they havn't been changed lately and theres a lot of miloes on them

try a change of spark plugs, ask for cold plugs when purchasing,you may have hot plugs fitted at mo, ok in summer but in winter.....can be a problem

Replace your Fuel Filter. Sounds exactly like you have Contaminated Gas and the Filter has caught the Most of it and has Gotton Clogged.