There will still be water mid July, but some things will be tapering off. Best bet is to get the whitewater of the southern rockies guidebook and start checking flows to see what things are doing. A gauge check when you get here can get you headed in the right direction.
If you plan your itenerary well, you can hit many different rivers, stay in one area for a couple days and keep drive times to 2-3 hours between areas. I wouldn't shy away from getting after it to see the best co has to offer
Around the denver area, bailey is one of the best IV/V creeks. Its flows are augmented by releases and it has been running at a great level. Blackrock section of clear creek is good start to the trip if you arrive in denver on the road trip. Also keep an eye on the big thompson if flows stay in the 400ish range. Good fun!
In the arkansas drainage, clear creek of the ark is great fun, but it might be too low when you get here. Either way, a run down the numbers to get a feel for some standard colorado class IV would be good.
Keep an eye on the roaring fork below maroon creek gauge for slaughterhouse / castle creek. Its a hop over independence pass from the ark and its fun IV+ creek into IV river near aspen. Good if the flows are over 1000, the more the better.
Crested butte is colorado waterfall central. Flows may be too low by then. Check mountainbuzz for visuals.
Durango area would be good as well. Cascade creek through upper animas would be a good bet.
Big South will be running then and its widely recognized as one of the best runs in CO. Its long and would be much easier with a guide. You can walk some big rapids and make it a top notch IV+/V day.
Finding partners may be more difficult during the week. Weekends should be no problem. Posting on mountainbuzz in the trip planner a couple days ahead could hook you up with folks.