Apologies if this question has been asked/answered before (I am sure it's a popular topic, so remove if not okay).
My boyfriend and I are planning to travel from Detroit to Kauai in late December. We should have gotten ahead of the game with a travel credit card, but we did not. Now, we are wondering what the best way is to book our flight. Something like the Capital One Venture X card looks great - 75k miles, BUT you have to spend $4k in the first 3 months - which I don't see us spending, even combined, before we need to book our flight. Additionally, I have some - not a ton, maybe 5k - miles leftover with United; they currently do have a "sale" on miles, and I am wondering if that might be the way to go - I can purchase miles at up to "40%" off depending on the amount (40,000+).
Just wondering what might be the best thing to do to use either points, miles, or others towards a flight. Of course, let me know if there are follow up questions I can address in the comments - and thanks in advance.