There are more hurdles to overcome where winter trail running is concerned. Shorter daylight hours, less appealing weather ...
I take about 15 trips a year by myself and don't leave without a cellphone tripod, back-lotion applicator, first-aid kit, or ...
A first aid kit should contain enough to deal with common minor injuries ... It helps you cope at work, 'heals' your brain, makes you more creative and it could even be better for you than running.