I'll make a pitch for calling in honest. A few years ago after the passenger bill of rights law, airlines would just cancel banks of flights rather than face fines for delays when weather got squirrelly. I was trying to go MCO-EWR on a trip when this happened. It was a winter storm and most of NYC was shutting down.
First thing I did when flight was cancelled was check backups, then I called CRS. Kept them in the loop. Decided to go to ATL and try to connect to EWR, JFK, or LGA if it was an option. When I got to ATL...everything from DC to Boston was cancelled. Chatted with duty officer, who pulled me from the trip. I told him I could NOT get to EWR, but since MEM was screaming for help (lots of open time) I did offer that if I could just get to MEM I would fly something for them. DO replied that once pulled from a trip, you could not be put on another except by waiver of ACP. So--I called my ACP, who said "thanks for letting us know, get to MEM, and get to work..."
Point to the story is I kept folks in the loop the whole time, stayed honest, and not only was I not disciplined or chastised but instead still got paid that night. They were drafting that night, but no--I didn't ask for draft--I just said if you will let me fly I'll go to work. And it worked out...
I think the key to deviating is have a back up or two, and if/when those look shaky be honest. I'm sure some EWR local got some draft that night, but the freight moved, the DO did his job, and the schedulers were happy.
Had a similar situation on the 727 years prior with a similar result. Didn't get paid for the trip, but that was all that happened.
No discipline, just an email going "what was your plan?" I had about 4 backups on Delta (to FWA from ECP...small market to small market) but all were weather cancelled with storms across the midwest. Got a reply thanking me for "good headwork" for keeping them in the loop and having a few backups, even if they didn't work that time.
Back in 2014, it was a different environment, and I quit deviating. I had an AA trip to Paris fall through when the MEM-DFW connection was late, and wouldn't allow me to make the turn in DFW. I ended up going First Class on Air France through ATL that night, and it was rather nice. It was also, as pointed out...."stress free" as it was not my problem.
So--deviate or not--you can make it work. Just keep everyone in the loop and shoot straight.