If you know when you want to Lance, bid captain for the first month, attempt to go in the last class of the month (much better for pay purposes and you will probably get most of your "captain" month pulled), and then just bid back to Lance the following month. That way you can back door Lance in any base that your seniority can hold (basically all of them). There is simply no reason to roll the dice with upgrade training and then take a pay hit with a Lance upgrade if you can hold captain anyway.

If you are worried about the commute, you will probably only have to commute for one or two trips which you can give away, trade, or just call out for. Don't punish yourself for the company's weird policies.