We dealt with that same recall, but were never offered a replacement vehicle. They just said, "don't drive the vehicle for a couple of months until we get to it." Ha!
I would guestimate your odds and make a decision with that info. Forbes estimates that the average driver gets into a accident one out of 18 years. (including fender benders) You say the failure rate of the airbag is less than 1%, and lets estimate that you will have to wait 4 months for replacement. If my math is right, and it may not be, your odds of getting in an accident AND have an airbag malfunction in the next 4 months are: (1/54)*(1/100) =.000185 or about 1 in 5,000 chance.
The odds of the toddler rubbing a piece of pizza on the back of the driver's seat, and stuffing a cheeseburger in the crack beneath his car seat are quite likely.
So, is the quite likely event of the toddler causing a $200 cleaning fee worth avoiding the 1 in 5,000 event that you will get into an accident in which the airbag fails to deploy properly? I don't know. After going through all this, I don't know what I would do. I might go with the new car, but only so I could get my new car fix, before going back to my lifetime of driving used cars.