Spiewak?
The nylon insulated snow bibs with the Sidearm/pocket access slots that overlap and velcro closed right?
Get ahold of Galls.
Lion and a couple others make similar snow bibs and Galls will have them.
For a while I took care of Uniforms and equipment for the last outfit I worked for, and Galls beats about all of 'em. Ours would get issued, and then the gang would hang them up to dry in a common area only to "Walk off", so we would go through 20K bucks worth of snivel gear annually.
If you aren't too concerned with the whole industrial look, Carhart is darn near impossible to beat. Berne and the TSC brand aren't too bad as a cheapo option, but they suck on attention to details like Curly mentioned.
I'm currently wearing holes in a TSC insulated Jumper that's OK, but it lacks the room/pleats to keep it from binding up when bending over or sitting, and chokes the crap outta ya half the time if it's zipped all the way up.
I can't wait till it's oil soaked and shredded enough to get another Carhart,
but can't complain as it was a gift from the MIL.
Last Carhart Bibs I had literally got burned by the wife, because she washed them without removing the duct tape and made a mess in the dryer..so she got rid of 'em in a way I couldn't rescue them.
Stay safe!
Dingeryote