How bad was the roads from Dolores CO to Pubelo CO taking route 550 to the 50 (Dolores, Montrose, Poncha City and Pueblo)?
Those are some mighty fine roads! I might be biased, I live in CO. May is a bit early, but those passes should be open unless you are very unlucky with a late storm.
I think your route goes over Molas Divide (10,910), Coal Bank Pass (10,640), and Red Mountain Pass(
11,018) on US550 instead of Lizard Head Pass(10,222) and Dallas Divide(8,970) on CO145 and CO62. The Western Express Route goes through Dolores to Pueblo, and takes CO145/CO62. The Great Parks Route goes through Dolores to Durango. ACA doesn't have a route from Durango to Ridgway were CO62 and US550 join, but this section of US550 is some mighty fine riding. Either CO145/CO62 or US550 to Ridgway are good choices, I have done both multiple times. Its a bit of a toss up but I think I would prefer US550. On either of these branches traffic is low, with the exception of moderate traffic from Cortez to Durango and the first 15 miles or so north of Durango, and a 9 mile section west of Telluride. Another advantage of the US550 branch is that you take a side trip to Mesa Verde National park. It is a bit of a chug up into the park (but nothing compared to all those passes), but I think it is well worth it to spend a day touring some of the cave dwellings.
North of Ridgway traffic is moderate until just before Montrose, then high in town. This is my least favorite part of your route in CO, but it is ok. Traffic becomes low again after Montrose through Poncha Springs. I haven't ridden the section east of Poncha Springs. The TransAm goes through Pueblo, Canon City and Parkdale, with moderate traffic around Canon City. The Western Express goes south of Canon City through Silver Cliff and Westcliffe. The Western Express route looks a bit less busy around here, traffic is denoted as low or very low.
You can see traffic volumes on the Colorado Bicycling and Scenic Byways map here: http://www.coloradodot.info/programs/bikeped/colorado-bicycling-maps
. Note in the fine print on that page that they will send you a paper copy.
You can see the ACA routes here: http://tsteven4.qwestoffice.net/
. The Web links are a bit slow but you may like that option best, you can select google maps as the background. I won't send you a paper copy, you but the ACA will for a few $.
I would expect cold nights in the mountains. For example in Silverton the average low for May is 26 deg F, the average May snowfall is 4", average snow depth 0". You can see climate history here: http://www.wrcc.dri.edu/summary/Climsmco.html