Forgot to post a follow-up with my experience.
We ended up parking along a surface lot along Mercer mainly for the convenience. Kind of pricey at $40'ish. We were going to split it but one of the guys got lucky at the Tulalip Casino on the drive back and covered it.
After the Canucks spanked the Kraken, there was heavy traffic along Mercer to get to the I-5 because of the traffic lights but at least it was moving albeit very slowly at first. Sped right up after the lights. Very convenient to get to the I-5 as mentioned above.

We went to the Shake Shack (South Lake Union) along Westlake Ave pregame which I didn't realize is very close to the Amazon Day 1 garage. We had parked by a meter and were debating whether to walk it to the arena from there. However, I think the meters have different hours during event nights?? Anyways, I think the Amazon Day 1 garage would likely be a preferred option if we decide to do this trip again.

Props to the very friendly and hospitable bars around the arena (buddies drank while I was DD). Also enjoyed the arena, the friendly staff, and even the Kraken fans; great atmosphere for a rivalry game. Lots of Canucks fans in attendance (likely doing a double header with the Seahawks the night before).

Many thanks again for the parking guidance!