Solo - yes
Caution - of course
Preparation - Essential
Succinctly and well put.
I like the trip plan form you have. I usually do mine by email. I send it to my wife and my sister. One of the things I like about email is that it can then be forwarded to SAR if need be.
I include an ACME Mapper link that shows my intended route. If you haven't seen ACME Mapper, it's worth knowing about. Here, for example, is
my route from last Saturday.
A little over a year ago, I ran (very) late on a trip. I had underestimated the length of time it would take quite seriously (it had been about 20 years since I had been in the area, and the trail had not been maintained for some time). My wife called SAR and forwarded them my email which contained an ACME Mappper link similar to the one above. I finally got to a point where I got cell service and called my wife. She let me know she had called SAR. I called SAR to let them know I was OK. They sent a truck down a service road to meet me part way into the backcountry. I apologized profusely since I had caused a SAR call out due to my bad estimate of time needed. One of the SAR guys replied, "yes, but at least you were exactly where you were said you'd be. We searched for a guy a week ago and spent hours before we realized that he had directed us to the wrong place." The SAR guys were actually quite pleased to have such an easy "rescue" even though I was thoroughly embarrassed.
Interesting thought: if I had had a SPOT with me (or Sat phone or HAM radio), all of that might have been avoided. I did by the way have a PLB, but a PLB wasn't very helpful in that particular situation.
HJ