I think the compromise should be determined by the conditions (temps as well as snow/wet/dry roads) on the transit legs back and forth.

• if you'll only see 40+F weather and dry/wet roads, get the winter tires in CO.
• if you'll encounter snow, esp deep snow, the winter tires will work much better than the all seasons.
• All seasons will handle some snow, but if the temp drops well below freezing, winters work much better
• in higher temp situations (say 60+), winter tires will generate too much heat from the sipes/deep tread and might literally fall apart (chunking). I think this would be particularly acute in a heavy truck like the x5.

2500 miles won't bother the tires much, except for wear. Note that real winter tires rarely come with a UTQG rating because they tend to wear pretty fast, esp in warmer weather.