Undo the battery terminals, clean them and reattach. Get the battery load tested.

But if it's turning over and not starting, I doubt it's the battery.

Sounds like a battery issue. Pretty much what everyone else has said. Good Luck.

I live in Montreal and my car starts at 0F. (-21 degrees C). Relatively speaking, it`s not cold in Texas. All my cars start just as easy in the cold winter. It was not the case 20 years ago - we needed to plug our block heaters.

Today, most cars are sold without them in Canada.

So - your car should handle your weather easily.

Truth, if it's turning over, it's not your battery...I can start mine in a lot colder temps than that (but I don't without plugging in the block heater for a couple hours first.

I think Jeff is absolutely right, not a battery issue at all:

Oh, and LOLOL at 35F described as 'cold'.

UPDATE UPDATE UPDATE
Heres the story
I took the car to the stealership and told them the problem. I get a call back in like 20 mins "Everything is fine sir it passed all the diagnostics" I told them keep it overnight and try to crank it the next morning. I get a call the next morning "You're right sir it doesn't want to start." Ugh duh if i tell u the problem u should listen. I get another call "ugh sir did you know your car can start without pressing the clutch" yes i do its disabled so i can remote start it. "Light Bulb IN MY HEAD" the damn alarm... I got remote start installed and we had to purchase a module from infiniti which u stick the programmed key inside to trick the car to start without a key.. So right away I call them back and tell them just to make me another key and see if it starts the car... They're response "That will be an additional 189.00 sir and its non-refundable meaning if that doesnt crank your car you will still be charged." I respond "Well if it does work will i be charged the $115 diagnostic fee meaning I told you how to fix it so i repaired my own vehicle. He laughed and said that was gonna be our next step. ugh yeah right. So the new key worked cranks the car no matter what the temp.
Speed up the story please...lol
Infiniti - Remove the alarm
Me - Cut the Key and keep the alarm
Infiniti - Why
Me- Because it doesnt start when cold with the backup key but will start with the new key.
Infiniti - Explain
Me - We are in Texas it will be hot again in about 2 months the car will crank with remote start or not.
Infiniti - Yes your right.. So what do you think the problem was sir.
Me - The module acts up when the compartment is cold "dont know why dont care" it works when it warms up.
Infiniti - Do you need a job?
Me - Lol
Done
Quick Notes
Car finally starts with new cut key.
Remote start module from "Nissan" fails when cold. So no start
Remove alarm ...NO it doesnt stay cold in Texas
Drives off lol
Thanks guys for all your help I was gonna go buy a battery but it just sounded powerful when cranking didnt seem like the battery was bad at all.

So did you take the job? That might be the quickest way to up your pay scale so you can afford to not live in an apartment.

my car does the same, i live in windsor ontario canada and its like -5 right now, every morning, my car cranks but no vroom, the car runs fine after that. if i shut it off and start the car in 2 hours later, it will start up no problem. Its only when the car has been sitting int the cold for a long time, the car has a problem starting up.

any insight?

if the battery passes load testing. it's more then likely the ipdm e/r. common issue in cold conditions in the Gs/FXs and somewhat common in the QX56s for no-start issues anytime. not a very cheap part tho.....the box behind the battery.

naw he was joking.. besides my business is progressing each month.. i see myself buying a house by the end of july.