Like all of the others, I too think your planned hunt for 4th season in a winter range is absolutely ethical. It is already a legal area for hunt so I know your focus is on the ethics of it. I feel your continued use of your muzzleloader only makes it even more closely a better hunting scenario.
My dad is 78 and still hunts. I plan on getting him out to Colorado in 2012 to hunt with me as I know time is dwindling for him to continue his passion... and me to be there hunting with him. I'm scouting an area this year so he can travel into and back out of the area with ease. I am following the regulations and even though I make it as easy on Dad as possible - I will still feel good about the hunt. And so should you. I hope your harvest next year is great and I look forward to reading about it!