That is an entirely normal scenario for someone visiting many of the most popular outdoor destinations in the US, especially in the west.
Planning a vacation where even after travelling to your accommodation you require at least 10 hours of driving over a 3 day period just to get to the places you actually want to visit is absurd and uncommon.
Since you're trying to be pedantic about trying to calculate the drive time for the distance, I'll note that (short of the unexpected WTF re-trip) it would have been less than 10 hours; I-75 speed limit is 75 in most of the UP, and the other main corridor roads have a speed limit of 65, because it is so sparsely populated.
For better or worse, the Upper Peninsula is this thing that your typical car-owning family who lives in the state can actually do an inexpensive but beautiful trip around.
It's a region that is only about 42,500 Square Kilometers but only has a population of about 300K. Thus the infrastructure gaps.
On the plus side, that means it's still a pretty drive at least. :)
I grew up in Ontario and I'm familiar with the area. It still seems like an absurd trip plan but you do you.
Though we're back to the fact that even in your worst case the most that can be said is it would be slightly more inconvenient given current charger network. In reality you'd problem just do a better job picking a base location or not choosing one given the distances if you were really worried.