You'd be wise to hunt on a clean barrel. BP and Pyrodex are hygroscopic and corrosive, and the other BP substitutes are very hygroscopic (IOW, they attract and trap moisture from the air which will rust your barrel). If your rifle is not consistant with a clean barrel, then you could hunt with a fouled barrel, but I'd recommend you carefully weatherproof the barrel (i.e. finger-cot, condom or electrical tape over the muzzle and tape or Saran Wrap over the action) to prevent moisture from entering during your hunting day. Followed by a full cleaning each evening as soon as you get home. It's a pain in the a$$, but sometimes you have to do this to ensure the one and only shot you'll likely get on game will hit where you aim it.
Or you could do what I do, and shoot your foulers in October and leave it dirty for the whole season...IF you shoot a Savage with smokeless powder!

Good luck on your opener. I'm going out for the first time this year tomorrow too. My late ML season started on the 17th, but this is the first opportunity I've had. I'm meat hunting this year because I might only get a couple days to hunt, so I plan on dropping the hammer on the first decent sized deer I get a clear shot at, buck or doe. I just want to fill my freezer.
Mike