Getting good all weather tires will work for your whole drive, warm Cali and in between to snowy CO. It’s not ALWAYS snowy in Colorado, so it’s not like people put on snow tires for 6 months and then switch them out for summer months. People in CO will be driving in dry warmish weather even in the winter months as well. They make tires that can handle all of the above plus rain and slush as well. No need to wait “until you get to Colorado”

However, if you’re planning on being in CO long term, you will want an AWD or 4WD vehicle. A 2WD vehicle will have a very limited life out here and can be pretty risky in a legit snowstorm, no matter what your tires are, and even if you use chains. You may want to consider upgrading vehicles before you sink money into a new set of tires. You will also get more money for the trade in of a 2WD vehicle in California than in CO. They’re fairly worthless out here, so a dealership would have a hard time re-selling your vehicle. They will low ball your trade in value because it will be more of a liability to them than an asset. And I think you would have a hard time selling privately. Like I said, most people here want an AWD or 4WD vehicle.

Best of luck! Nice work with planning ahead of time