Yeah gym cardio isn't the best, but I find the ellipticals to be alright, it's what I do (when I'm not going on a mountain hike anyway which is infinitely better). The elliptical is so low impact on your joints which I like since I'm 34 and starting to feel that shit. I just try to get my heart rate to around 150 and keep it there for 20-30 minutes, depending on whether I did weight stuff that day too. It's not bad man, put on some music and it's just an opportunity to listen to music and get in better shape.
If it's slippery, running isn't gonna be good probably. Do you have hiking opportunities where you live? My favorite exercise is a good, strenuous hike in the mountains.
You can do stuff (indoors or outdoors) like jumping jacks, calisthenics, etc. There are things you can do, you should look it up if you're not open to using gym cardio equipment. Loads of stuff you can do at home.