Bike Commuting: The Problems of the Ride Home

I have lived car-free at various points in my adult life, sometimes by choice, but often because of practical considerations. During those times I've tried very hard not to be the "Bum a Ride" guy, who is always asking his friends and family members if he can "bum a ride" here and there. The rare occasions when I do ask for a lift I try to pay for gas and parking at least, and make sure I don't inconvenience the person driving me any more than absolutely necessary (especially having been on the other end of that transaction, when a car-less coworker relied on me for transport to work, and was late almost every day, it was infuriating).
My current job requires me to work evening hours, which means I have to bicycle home in the dark. Because of this, and the usual misconceptions about how dangerous bicycling is, I occasionally have friends and coworkers offer to drive me home.
Most of the time I'm not even tempted, it's only about a half-hour bike ride, and during most weather conditions it's a fairly pleasant way to unwind from a less-than-wonderful job. Even when it's a bit chilly and/or rainy I'd still rather bike.
However, there are some conditions which make getting home by bike a bit more unpleasant and dangerous than I'd like, most notably thunderstorms. While I feel reasonable secure among downtown buildings and trees, there are some exposed hills and bridges on my ride home that I'd rather avoid those times.
Unfortunately, my bike is pretty big (I'm tall, and too heavy for most of the folding bikes out there) and doesn't fit in most cars without extensive disassembly, so accepting a ride most of the time would mean leaving my bicycle behind, which in turn would leave me stranded without transportation in the morning, as well as cause an extremely high risk of my bike being stolen.
I've lucked out on the most recent occasion by having a co-worker with a pickup truck, however there are times when I may not be as lucky.
Some of you may have a spouse or significant other who can pick you up, but what about those of you who don't? How would you handle the leave-your-bike-or-ride-dangerous conundrum? Also, are there those of you out there who are car-free for ethical reasons who wouldn't accept a ride under any circumstances?