I've had commute routes as long as 45 miles each way. Most days I would ether drive or take the bus part way then ride the rest, but in the summer I would do the full monty 1-3 times a week. Another tact I used to use was driving to work with the bike, then riding home on the bike, leaving the truck, riding back in the morning, then driving both back home...rinse and repeat.
Your body can get used to it easy enough, just like it does on long tours...but the time that it takes out of your day is more problematic.
My best advice is to stage as much as you can at work...toiletries, shoes, clothing, food, drink, etc., using driving days to replace/replenish, so you can ride light, fast and easy.
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"Let us hope our weapons are never needed --but do not forget what the common people knew when they demanded the Bill of Rights: An armed citizenry is the first defense, the best defense, and the final defense against tyranny. If guns are outlawed, only the government will have guns. Only the police, the secret police, the military, the hired servants of our rulers. Only the government -- and a few outlaws. I intend to be among the outlaws" - Edward Abbey