My wife and I are thinking if going to visit family in Fort Lauderdale in Jan. My son is under 2 so eligible for as a lap child but me moves so much and hates being held, it’s not a realistic option.

Willing to pay for the 3 seats (us and car seat) in F for the extra space but I can’t find anything online to confirm that they are allowed in F.

Which leads to question 2. If they are, the flights vary from A320, to 737 and a 757 200. Obvious the 757 w flat beds would be the nicest, but do those lie flat seats have restrictions on it? I reached out to United and crickets.