I have a 2014 polaris Efi 550 X2 EPS that had continuous trouble starting in cold weather conditions.
After 3 yrs my local dealer finally figured it out.
There are parts of the fuel injection system polaris out sourced to different manufacturers that fail in cold weather.
There is something like 5 or 6 different electrical components that make up the system and I believe they switched out 3 with polaris made parts and haven’t had a problem since.
Parts are on the cheap side but labor is where it gets expensive.
My wheeler was out of its warranty but since I took the machine into the dealership each and every time for its reoccurring problem and scheduled maintenance they had a record of it and covered the cost of the repair otherwise I want to say it was going to be around a $400 repair.
Other than that electrical issue it’s a solid machine with no other problems.
Hope this helps!