I did a solo caribou hunt with Illiamna Air Guides some years back. It was everything I was looking for. With their tundra tired Super Cubs they will put you in the middle of the caribou herd, no matter where they are. They will find them.
At that time I had to ship all my gear up ahead of time, but now they have tents and other gear for rent, much more convenient.
I killed a great caribou the day after being set down. (you can't hunt the same day you fly)
A solo caribou hunt is certainly okay to do but you really need to be prepared. It's a big chore to take care of a big bull by yourself. You have to bone out all the meat while it's on the ground and then pack it all back to camp. You could easily end up a mile or so from camp.
And it is always risky hunting alone. Just do your best to be as careful as possible, and don't take any unnecessary chances. Use good judgment the whole time. Now days with GPS and satellite phones I would feel a lot better. I've always loved the extra challenges of hunting alone and the solitude with nature. To me it's not scarry at all. Driving to work on the freeway....now that's scarry!
Good luck,
eelgrass