I would say yes but the question is do you really want to and I Would still treat it as loaded if you did

I have in the past left a hunting load in for 2 nights and still had it go off with little delay.
If by chance you’re worried about condensation getting into the charge put a peace of plastic rap over the nipple and let the hammer down.
I recently bought one of those Co2 dischargers and it works great, simply pops the round right out in my flintlock. I also tried it on a friend capper this fall and it worked just as well.

I often leave a load in my gun during hunting season. The key is to keep the load dry. I hunt Utah, and the weather here is pretty dry so I usaully don't have to worry. However, if I'm hunting in rain or snowy weather, or there is high humidity (over cast), and a lot of condesation in the morning, I'll start with a fresh load.

I never leave a cap/primer on a loaded ML.

Do I treat the gun as loaded? simple answer yes! Do I treat the a gun I just got through cleaning and know is unloaded, as loaded? yes! But I don't think that is what you were asking.

Here in Utah a ML is not legally loaded until you put the cap/primer on the gun. But this could vary by state, so check you local regulation. So from a legal standpoint you can do what you want.

Safety- besides the obvious, if you have a load in the barrel but the gun isn't capped, you must gaurd against sparks or flame from getting to your load. Things like campfires, smoking, heaters all could pose a risk of touching off your load if you got your gun too close. Otherwise IN MY OPINION a load in the barrel, but not capped, is very similar to a cartridge in the magazine.

I always leave my gun (a caplock) loaded until I either get a shot at game or the season is over. Whether I fire the gun on the third day of hunting (as I did this year) or at the end of the week it has never failed to fire immediately.

Always treat the gun as though it is loaded. I also always put a piece of electrical tape over the end of the barrel after loading in order to keep it clean.

My gun is a traditionally styled Lyman Great Plains Hunter in .54 caliber.