I know this might not be the option you were considering, but this is what we do..

Last year we flew AA one way and United back using miles. We have 3 people and it was hard to find 3 "milesaver" type fares in the summer with kids.

This year I decided to make a stop over on the west coast. Might not be your first choice, but I was able to sign up and get Hawaiian miles and also Alaska miles. I also signed up for a Southwest card for the bonus. We live in San Antonio and Hawaiian and Alaska do not service our area.

So we flew for free to the west coast, stayed overnight using points, got up the next morning and flew Alaska to Hawaii. (we actually used my hubbys AA miles for the Alaska flight). So it was 40K Alaska miles (which I got free for getting the card). And 22.5 AA miles or the flight....

On the way back I used 52.5K miles for 3 one way tickets back to San Fran. I got these miles by signing up for the Hawaiian card along with my husband. Had extra for our interisland flights...

I used miles from Southwest to get from the west coast back to Texas. You can get these either from getting a Southwest card or a Sapphire Preferred 50K bonus and transferring them....

Just some creative ideas... I also like taking a mid day flight back from Hawaii versus a red eye. Last year we flew Maui to Denver red eye and hated it. This year our trip was so much nicer with a stop over on the west coast, especially with kids!!!! We actually spent 2 days in San Francisco on the way back just to break up the trip!