My bike is S&S coupled and fits in a hard-sided case that I need at the end of my trip to rebox the bike for flying.

On tours where I am starting and ending at the same city (either loops or taking transportation to starting or ending point), I have left my case in a motel by agreeing to stay there at the start and end of my trip. I've done this in France, Switzerland and Texas.

On tours where I am ending at a different place than I started, I usually post the (empty) bike box to the ending point. Usually, I try to find someone from warmshowers.org or couchsurfing.org that is willing to accept delivery and hold the box for me. Since this is done within the same country (usually), the shipping costs aren't all that high. I have also shipped my bike box to a motel where I plan to stay at the end of the trip without problem. While it is a bit of hassle and requires planning, I've done this many times.

I've flown with my wife to my starting point, spent some time sightseeing, she's flown home with all her stuff in my bike box, and, at the end of my trip, she's flown out to meet me with the bike box.