Remote no longer works

I noticed a while back that when it got cold the remote would stop working and when it warmed up it would start working again.
Now that it has turned cold I cant get it to work anyomre.
I have to use the key to get into the Envoy and press the lock button to unlock the doors, but this does not unlock the back hatch or back glass.
I have taken the fobs to Oreilys and they test ok.
Any suggestions?