Get a wind-up travel alarm, if you can find one these days. I used the same $10.00 Bulova for 20 years. They work great and never have dead batteries. You're a smart guy, you can figure out the local time and set the alarm accordingly.
" Gee, I'm sorry I didn't make pickup, but my alarm clock ( cell phone...) batteries went dead and the front desk didn't give me my wakeup call ( what a big surprise, huh ??? ). "