There is a thread on this topic almost as often and as predictably as a "What Is Wrong With the Courtyard Brand" threads. (We're overdue on that one by now, but nothing is new so please don't start one). Trying to remember some of the suggestions the board has offered in the past that might help somebody rather than joining in and reciting the times I was sinned against and had the same problem. In no particular order, and apologizing to the posters above who made the same effort:

1. If you have any real credit history of paying your bills and need unlimited funds for a short period of time, you need a regular Amex. You can afford $95 a year if you run that much through it. (If you travel internationally, you really need an Amex).
2. Ask for a credit line increase. (If you pay it they will throw one at you soon enough anyway). Shop for a better hold policy if you don't like theirs.
3. You really need more than one card anyway. Offer one as deposit and switch at checkout. Leave one locked up in the safe in case of card loss just to get you home.
4. Monitor the hold activity and ask for mistakes to be reversed before you leave.
5. You are telling me your employer does not have any way to remotely turn in expenses and get paid before you get home from a very long trip?
6. Nobody said you can't pre-pay your card to clear out the credit line or create an overpaid situation when you expect to be tight.
7. I know you want the points, but take the company card at least as a backup.
8. My personal favorite I had to learn, update your running expenses account every single night so it can be finalized and turned in on a drive-by basis.

There are two philosophies of travel on this board, which I will relate to as "Dad" and "Mom". Dad drove very long distances in a bad two-lane world every week as part of his living and learned to look down the road and adjust his behavior to mitigate problems. He came to completely enjoy himself doing it. A long road, a full tank of gas, an open window, and he was at peace in the present. Mom though she had paid her road taxes and was always surprised by the bumps. Dad was way more fun.