Hopefully you will get better answers from guys who know a whole lot more than I do, but just in case:
It depends on where you start from. It is a big lake. In some places you can fish within a few yards of shore. Other places, it can be quite a hike. Same answer about depth. Pick a decent Saturday and see where others are fishing. Most folks are super friendly and will share what depth and what rigs are working for them.
Everyone has their own "go to" rig. Maniac gazillas, jig-n-raps, tear drops, Swedish pimples, just a worm all seem to have their day. Stop and talk to Tom, he can and will give you the best advice as to where and what to use.
It isn't the ice so much as the snow / slush / standing water. I can only speak for walking in, currently you had best follow a well packed snowmobile trail. Breaking trail on foot pulling a sled for more than a short way is a daunting task at best for me. But then I am closer to 70 than 60 and in dog suck shape...
Only thing I have ever caught at Cascade at night were bullhead. But that is just me, a pretty small sample.
Cell phone coverage is excellent.
Occasionally you will see a shantie out overnight, but not real common.
Good luck. Hopefully some of the better fisherman will chime in with some better answers for you.