As you drove up to your in-laws' home, were they on the front porch shaking their heads and looking down at the ground, not understanding why anyone would want an electric car? Then did you give them rides? What were their final impressions (especially father-in-law)?
When I got my SE in August 2020 I looked at the possibility of making the trip from the Twin Cities to Albuquerque, which wasn't possible. I recently checked again and it now is possible, so the charging infrastructure has been improving. The hardest part seems to be going across New Mexico where the chargers are spaced a bit too far apart for the SE, especially through the mountains. Electrify America does have DC chargers along I-40, so hopefully that will continue to expand.
My experience of using the DC fast charger. First time to try using a DC fast charger at the Petro Canada gas station. After plugged in the CID in the car said I need more than an hour to charge from 67% to 100%. I was stunned! So it is not fast charge at all! Now I know that after 75% of charge it becomes verrrrrrrrry slow. As the charge is based on time used, in my case it was CAD0.33/minute. Lesson to me is never charge it to more than 80%.Unfortunately for that rule of thumb, travelling at 75MPH, that implies charging the SE to above 100%.
As far as only enough range for the next leg keep the charge curve in mind. The rate actually continues to climb until about 75% where it starts ramping down. So it would be marginally faster to charge up to 75% even if you don't need it. You'll arrive at the next stop at a higher SoC, which means you'll start at a faster charging rate, since the peak is at 75%.
Anyway, my way won't save you much time. But I'm an engineer so optimization is what I like to do.
Sadly, Honda just announced that the end of the line for the Clarity has arrived (don't tell my avatar). I expect any PHEVs introduced from now on will be cross-overs and SUVs, not cars. Glad we have our Clarity for when we start doing long trips again.