My heart goes out to you all and a big hug to all of you out there.
I do have a few ideas though that may help!!
Wear a onesie on them BACKWARDS!!
Seriously, get a size larger if necessary. Gerber makes onesies in larger sizes and you can get the onesue extenders too for a bigger toddler. The child (in theory) should not be able to read the crotch snaps if they are in the back.
Onesies at Babies R US
Onesie extenders at onestepahead.com (One of my personal favorite online kids stores)
Use Mitten clips for fastening their shirts to their pants or shorts!! Yes, I know it is a crazy idea but it should keep the clothes ON!!! That is what is important!!
I found these and other childrens clips and Suspenders at the Suspender Store
I also found them on amazon.com
Suspenders could be a huge help too, and they make them in many cute parrents and colors!!