I trust Luke completely, and he has been hunting solo since his teens, but I confess I still worry when he goes solo. While I am still not wild about the idea, several things have made a big difference for me in feeling more comfortable when I know he is out there alone.
First and foremost is communication, before, during and after. Before he goes, we try to discuss where he will be going, where he is going to leave the truck, how long he plans to be out, etc. basically it's like a trip plan, and I find that knowing where he is going to be gives me some peace of mind. At least then if something happens and he becomes overdue I know where to start looking. We have a sat phone, and when Luke goes alone he calls in every night (this is a change from the norm for us, if he is out with other people but without me, he often only calls every couple of days or so). They don't have to be long calls, but I feel so much better knowing that he is ok out there. When he calls in he updates me about where he is, particularly if this is a change from the plan we have made, and gives me some idea where he is headed the next day. He has also gotten good about letting me know when he gets back to the truck, after a miscommunication years ago that had me pretty worried. For my part I have tried to not be too irritated when he comes home later than planned, as long as he keeps me updated.
If a sat phone is not an option for you, an "I'm ok" message from the spot, or other device could achieve a similar goal, but you can't communicate changes to the plan or find out if there has been any kind of emergency at home. For where we live and how much time we spend in remote areas, the sat phone has been more than worth it, but I know it's an awfully big investment.
I think the other thing that has been most reassuring to me have been unsolicited statements by Luke that no animal or trip is worth dying for. He has made a point to tell me that he is even more careful than usual and takes fewer risks when he is alone, and I believe him. The stakes are a lot higher when you are out there without anyone else.
I still worry whenever he heads off solo, but these things have made me more comfortable with the idea. It also helps when he comes home safe, and tells me it would have been more fun if I had been able to go
