^ Your proposed I-40, I-25 route is about 268 miles longer than the more direct route via I-70. It does avoid high mountain passes. Yes, you can hit snowstorms on those highways — the worst snowstorm I have ever driven in was on I-40 between Grants NM and Albuquerque, but it was a fluke: had I been two hours earlier or one day later, I would have missed it entirely. Most of the time those highways will be clear and dry — you need to time your trip to drive them then.
My suggestion is to be flexible and keep an eye on the weather. If it looks bad just stay put and wait a day or two (or leave earlier, if that works). If the weather is nice, the shorter route via I-70 will be easy. Colorado is very good at plowing and sanding roads after a snowstorm, so if you wait until a day or so after a storm, you shouldn't have much difficulty, especially if your M3 is AWD (as opposed to RWD). If you try to drive in a snowstorm, yes, you could need chains. However, it is much better to stay off the roads for a day or two until the snowstorm is gone and the roads are clear. Roads in the sunny Four Corners states do not stay snowpacked all winter, even in the mountains.
For Colorado road information, including dozens of webcams of road conditions, check out cotrip.org. I would guess that other states have something similar but I haven't needed them because I try to time my trips to the weather.
Please be aware that if you do try to drive in snow, getting going is not the problem. The problem is stopping and turning and AWD doesn't help much with that (only snow tires or chains, plus experience, will help). Best to just stay off the roads when they are slick.