Well,, I should be dead a long time ago too.
My survival did teach me about how to crash well, steer good enough ( like drifting sideways) to avoid a crash, and wear helmets and armor for higher speeds. One motorcycle I rode had nothing but a rear brake, and not a very good one. Did nearly die on it many times.
My main problem here on this thread is simply that while 40 mph electric bikes can be cheap, one that goes for very long range at 40 mph or more is anything but cheap. $5,000 cost is not crazy talk.
To race at 40-50 mph, I carried 100v 15 amp hours. 1500 watt hours. Not really that big, but still a solid 30 pounds of battery. It was just enough for 11 race laps, on a one mile track. About 120 watt hours per mile. Handing got very bad packing 30 pounds of battery, and I did crash out on that race. ( the previous race I almost won, with 20 pound battery, but only 40 mph)
But at 30-35 mph cruise speeds, your draw drops to the 60 wh per mile ballpark, and range is enough to get someplace and back again. And bikes handle 30 mph no sweat.
Again, build it for 55, I do not object to that. then ride it slow enough to get home, depending on the ride. Otherwise, you WILL NOT be buying anything like an affordable battery.
Sounds like you can sneak the e bike on the Amtrack if they don't notice its got a motor. ( hide a hub motor with panniers like my cruiser) Carry on your battery. You can do 30 mph with a very small, easy to hide rear hub motor. You might find that when you ride for the scenery, 15 mph is the best speed to ride. Now a 30 pound battery lasts 60-80 miles, instead of 20-30.
And again,, keep that gasser as is.. start over on the e bike.. That gasser is too good to change, unless its to make it faster.