Depends how cold. I ride my scooter through the winter and if it's below -3C (28F) I spray some starting fluid on the filter and use a kick start. Also, the air/fuel mixture for starting is different from summer and winter.
I have a 2014 icebear trike. I had similar issues with mine in the warmth of Texas winter. I ran across a video on youtube.com and simply made an adjustment as prescribed in video and have had no problems since. Before you spend the bucks, take a few minutes to review the setup procedure.