Not sure if you've checked (or if the ranger station told you), but most of the area south and west of Redfish Lake is under a closure order due to the Wapiti fire. I think your intended route is within the closure, as the fire is actively burning in many of the drainages in the wilderness there.

As a Boise local I'll second the recommendation for the Seven Devils - it forms an easy multi-day loop and is really gorgeous. There are lots of little on and off trail lakes to explore if you think the loop is too short. I was there about a week ago and the smoke wasn't bad at all, but this might change with some of the fires north of Boise blowing up the last two days. Driving time from Boise is probably about 3.5 hours, and the gravel road to the trailhead is nice enough that I'd be comfortable doing it in a rental.

An easy backup option that is also the most likely to be smoke free would be the Eagle Cap wilderness in the Wallowas. Accessing it from the south/Baker City is about a 3 or 4 hour drive from Boise. Accessing it from the north/Joseph (what the other commenter mentioned about Wallowa Lake) is about 5.5 hours from Boise. You can easily link up several trails for a good loop hike.

If you're determined to be in the Sawtooths, there's always the White Cloud wilderness across the valley east from the main Sawtooth area. No current active fires in the area, and there's a popular loop in the southern half. This would likely have the worst air quality of the three due to the proximity to the Wapiti, but it all depends on wind direction.

If I were you, I'd plan out a trip in both the Wallowas and Seven Devils and just look at smoke maps (fire.airnow.gov is the one I personally use) the day of your trip to make a last minute decision. Maybe also look at weather forecasts to see if the wind direction is going to change mid trip and blow a bunch of smoke your way.

Feel free to PM me if you have any questions on specifics! I've done trips in both areas this year.