The people of the area you are bugging out to are an important consideration. If you are a stranger with no social connections and the S has HTF you may be considered more of a source of supply than a welcome guest.

Are you planning to walk it once to see what it's like?

GPS is good to use when it's available, but I wouldn't rely on it being available during a bug-out.

(I'm not planning a route myself because I'm not really into the whole bug-out concept.)

The bug out route and destination are very rural and agricultural. Way more cows and grapes than people along the entire route and alternates, and ending in a very rugged river canyon in a wilderness area. Even driving, all towns could be avoided without much trouble if advisable.

I kmow the route very well, having seen much of it it by boat, most of it car, and key areas on foot. I am confident I could get there without any map or compass, or GPS. From where I live I go north until the first river, then east until the first and only tributary river, then follow the tributary river upstream.

In ideal conditions I would drive / ride most of the way there. If surface vehicle traffic conditions were prohibitive, I could boat from my current residence backyard to the destination river before having to go on foot.

The journey cross-country on foot would not be nearly as quick and would require getting across one river that is crossed by several bridges in rural areas. No flood in the past 100 years would have blocked my destination, but would limit the number of alternate routes for the first thrid of the distance.

My hope is that I would detect a bug out situation and dash to my retreat before others really considered the situation.

I've picked up a lot of maps and researched a lot around my main bug out route. Since my farm is in another state I have about 250 miles or 1/2 tank of gas during normal times. Detours, slow moving off road, traffic jams, etc will stretch that out.
I've started mapping out all the parks along the way and make day trips there so I get more familiar with back roads and interesting things along the way. Handheld gps logs the route along the way so I just have to take a picture of anything that looks interesting and match up the picture time with the gps log.