Traveling with baby

Ok, so i have a few questions about traveling domestically with a 5 month old.

We are traveling from NYC to Fl. The flight is 3hrs long. He usually eats then can go for about 4hrs before needing another hit..😂.

Now my questions are

1) should i buy a travel bag for my stroller?

And 2) how do i travel with formula? Should I prepare it, or leave it in powder form? And either way, how do i warm it up in the airport?

When I’m out and about at home, I usually fill a thermos with boiling water, to warm up water than mix & give. He hates cold anything....