A few years ago I had the same concern so I waited for the large safes to go on sale and bought one. If they can get it out of my basement then more power to them as I know waht it took to get it down there.
When not in use, mine are always secured in quality safes. If I'm on vacation, my nearest neighbor keeps an eye on the place for me. By the way, my neighbor is a retired scout sniper. I've absolutely no worries!
When I leave my house, especially for long periods of time, I thread a medium duty rope through the trigger guards of all my guns and then dangle them in the front window like tinsel on a Christmas tree. I even leave the living room light on so they are easy to see. So far it has worked pretty well. Thieves are lazy but if something looks just a little too easy, they walk away because they think they are being setup.
At this point in my life I have a decent safe in a secure location. I just ensure everything is in its place, and lock up, same as any other day when I leave for work.
There was a time that I didnt own a safe, and couldnt afford to just run out and buy one. My Gun security at that time was a series of eye bolts ran into the wall studs, and a cable lock that ran through the guns in my closet. When I left on a vacation, I took my guns, cable locked them together in the trunk of my car that wasnt going with us, running the cable through the body of the car as well, then locking the car up in my garage, that faced my neighbors house and a busy street.
I don't do vacations. I went to Ozarks in 2004 for 3 days, that was my last vacation. I haven't been on a trip longer than overnight since then. I lived in Chicago and didn't own guns at the time. But, gun ownership has nothing to do with my decision. I work with people for a living. If I were to go on vacation, it would need to be somewhere that people tend not to congregate, so I bought a decent (for the area) plot of land. People tend not to congregate on my property, so that's where I choose to spend my time away from work. Plenty to do here, plenty of hobbies.
If I were to take a trip, I would need someone to "staff" my house. My animals can't be left alone, need chores done at 5a and 7p every day. So, if I were to go on a trip, the couple guns I own would be in the safe and someone would be staying here to tend to the animals.