The Upper Delores below McPhee is a pretty slow section. There's only one rapid of significance, Snaggletooth, and it's probably not worth making the drive from D-go until it gets higher (like 1000 cfs or more). It's a good place to take beginners, but there are long sections with flat water. At 500 cfs, you're talking Class I or II with Snag being a III- . And the shuttle is a muddy dirt road with giant puddles.
The section above Stoner is what you want- playhole after playhole, and it runs early (mid-april to mid-may). Put in at Bear Creek and take out at Stoner.
If you want an adventure, watch the gauge on the Piedra. If it gets that warm in town, the Piedra will probably rise above 800 at Arboles, and it's boatable at that flow. You'll have to do the whole 20 miles, but it's kinda fun and creeky, and the hot spring is not covered by the river. Plus you get to scout the run before it starts ragin' in May. It's also a beautiful canyon- but start early, because it is a long day....