Sounds like you guys did way better than we did.
Went up with my dad and uncle, fished Thursday-Saturday. Dad and uncle don't seem to want to get up early any more so we were a little late getting setup every day. Every day was a grind, until about 6pm. We moved 10 or more times per day, tried depths from 8-18 fow below the ice. Found baitfish and marked quite a few smaller fish in 15-16fow, but nothing really active and chasing the baitfish. We were just on the east side of the mouth, directly north, and on the west side.
10fow below the ice seemed best after 6pm. We caught 90% of our fish in the evenings. I think I caught 24 fish total in 3 days, one 26", 28", and a 28.5". The 2 28"ers came Saturday evening in a 15 minute span, kind of salvaged the trip for me. Green bait ball tipped with a minnow head did the best for us.
I had the tracked atv and dad and uncle had wheels on their atvs. Travel was a little rough, especially moving east-west, but not terrible. Snowpack was hard and they had no problems getting around on wheels. There was a surprising number of trucks and suvs traveling out to the mouth on Saturday. Big caravans all going out, they really beat the crap out of their vehicles. I should've taken a picture of where they were crossing the ridge, I don't think I would've gone through there with an ATV. 1 extension was fine 95% of the time, I only found a couple times where it wasn't enough.
Sunday I got up early and drove another 75 minutes north to Hecla Island. Accessed at Gull Harbour and fished off a point. Water is clear up there, and good structure. Caught 4 small walleyes in the first 1.5 hrs and then tried a different spot, a reef off the shoreline with big boulders on it. No fish there. I was the only one fishing those spots, but there were 30 or more people fishing on a different point. Current is present and first point I fished only had about 16" ice. Interesting area for sure, not sure if the big walleye are in that area this time of year, kind of kicking myself for not driving over and talking with some of the other guys up there.