Well..... you'll get some 'yes' and some 'no' replies so there's no definite answer.
The 'iffy' part for many is between Ouray and Silverton - a short distance but southbound you'll have the drop off on the passenger side. Get a eye mask for her!!
From Silverton to Durango is much easier.
We've done the drive both directions with our 40' MH but we're in mountains all the time so no issues. It just depends on how you are about it.
There will be a couple big pull-offs on your downhill before Silverton so you could do that and take a deep breath before carrying on.
While you're in Ouray you'll surely have a chance to drive it in your toad which you should do to get the 'feel' of it. You can always take Hwy 62 from Ridgeway to Telluride and Hwy 145 south to Cortez then 160 east to Durango. It's still mountainous but not the drop-offs as in the first section of 550.
Oct is getting late for high mountain driving so keep up with weather reports. We've been there at that time with good weather but each year is different.
Have a good trip..... a favorite area of ours. We've spent just about a whole summer/fall in Silverton. Awesome Jeeping! Take a tour if you can or rent a Jeep.