Well I would say that the point of a PHEV is to allow total electric driving virtually all the time if your daily use is 35 to 38 miles or less until you can return home. So you could in theory never use any gas but of course in that case you might as well have bought a used Leaf or something with only 100 miles of range or so for probably $10,000 or less.But a PHEV simply lets you do that but then still have the same hybrid when driving on a long trip. Also on any long trip, if you wish to be kind in driving through cities, you can simply drive in sport mode when you know you are 50 minutes from the city and you will arrive there with a full charge. With gas less than $1 a litre here in Canada and mostly less than $2.25 a gallon in the US any small loss in mpg while charging is well worth it and pretty much a wash when you then drive on the recovered electric charge. The average Mpg will shoot back up drastically when you drive for 34 to 38 miles on electric again through cities or heavy stop and go traffic.Not got the PHEV but my hybrid will do 600 miles and more on a full tank . Just begs the question " What's the point of a PHEV ? " , especially in the UK where it's about £8000 dearer than the Hybrid in the UK .
Not a criticism of your post just an observation
you mentioned 8000 pounds difference in price which is nearly $14,000 in Canadian money. The difference here in Canada or the US is nowhere near that amount. Have to speak to my Hyundai dealer this a m so I will ask and let you know.
Just some alternative thoughts from my own experiences with my Ioniq.