Men's shoes when travelling if there is a mix of formality for meetings?

I looked but did not see an answer to this question...

I really like the Manager Tools idea of wearing black flannel pants rather than khakis to cut down on the ironing. However, what kind of non-running shoes would you recommend if you are going to different events on different days on the same 4-day trip (i.e., leisure, business casual, and then slightly more formal)?

I will be in Washington on Sunday (late September). I will check-in and spend the day playing tourist and then catch up with a professional contact in an informal context over dinner. Normally, I would bring weekend shoes, but I can wear business casual shoes (i.e. black blundstones boots) to cut down on the packing. I will then be at a conference on Monday and Tuesday with international development types and consultants but business casual shoes would still be good.

Now, it gets tricky. I will be meeting a U.S. government executive on Wednesday before travelling home. This is a first meeting and I expect that he will be wearing a tie.

I can cut down the number of shoes on the trip by wearing business casual shoes for Sunday, Monday and Tuesday. I can also manage by wearing a more casual, button-down shirt at the conference. However, I feel like I should dress up a bit for the meeting on Wednesday. I can dress a little more formally by wearing a solid white shirt but I am starting to stumble on the shoes. Back home, I would be wearing a tie, conservative shirt & tie, and black oxford dress shoes.

What kind of shoes/boots would work for both business casual and first meeting with a US government executive if I am wearing black flannel pants?

The podcasts have Mark packing running shoes and presumably business casual shoes.

(My apologies if all of this has already been covered, and I missed the forum topic.)

Any thoughts?

Thanks
David