Tailwinds don't count *shakes fist*
Actually, TBH they can & do when considering range... and that can get dicey as we haven't the super spiffy gauges to help calculate reserve.
As your lil tropical island paradise is smaller coast to coast than your maximum range, this may be less an issue for you unless you're out n'about just wandering on a really windy day - but jus' last weekend I was headin' over to a friend's house and the winds were so strong it was a bit of a struggle, I was loosing up to 5mph off my normal top speeds...
...as my friend's place is at the very edge of my "point of no return" (half my max range) I started to grow a bit concerned, without a doubt I was consuming far more then the norm, it was becoming increasingly unlikely I'd be able to get there and back again on this single charge - even though you'd think if you've a headwind headed out, you'd have a tailwind heading back... but as any sailor will attest, such things can't be trusted and that's doubly true in Maine, where we've schizophrenic weather at best lol
Well, I got there anyway... took a lil longer than normal but that's not a problem & I knew I'd at least get there as again it's only the PNR, catch is - nobody was home ofc.
Doom? Hardly - whatever, no worries, I just wandered off to get some water & munchies & sat in the shade contemplating little to nothing at all whilst I charged up for an hour or so, snaggin' a lil more zot to be sure I'd get me home... and wouldn't ya know it? Naturally, there was a headwind all the way back again lol
Some might say that this is an example of an ebike's shortcomings... and that may be true - then again this jargon seems awful familiar, this consideration regarding head/tailwinds, PNR, max range vs speeds, etc., it occurs to me that it's little different then when I was piloting, be it the ol' Cessna or my itty bitty ultralight... come to think on it a bit the same holds true for boating & currents, heck even wandering the outlands on my gasbikes, where gas stations are a mythical tale told in jest...
Granted - the maximum ranges & time to refuel may be different, but that can be said of all these things & I've long ago learned to not worry the hurry heh *shrug* If I wanted farther/faster I'd have a different tool for the job