sounds a bit like little big drama ...
here.
my GPS never failed, never sent me the wrong way, nor was it stolen, nor have I lost it, nor was the battery ever empty. my tours I plan on a 27" screen at home, every single meter manually online with a specific cycling map, I decide all details, all turns, all roads, no automatic routing, never.
the online cycling map shows me many more roads than a paper map ever can. if posible wile planing I look at google street view to see how the road looks like. you will never ever meet me on a 8m - 10m wide road cycling, if so its a short ride to "connect" two rural roads.
If on tour I change something I do it with the phone, works also top. And when the big drama day comes and my Wahoo does not work anymore, well .... then I will use the phone, where all tours are saved for offline use.
have a nice weekend.