I consider myself a bit fortunate in that I had some instructors at about the 200hr mark that taught me to relish the difficult rather than the easy, and how to develop the mindset and skills to deal with that.
Safe vs Legal: personally I would far prefer to fly under a 400ft base with good vis than under a 1000ft base with less than 5000M.
I probably wouldn't fly in much less than 5k unless I knew the area well.
And those sorts of minima (for me) vary with type. Eg 172 happy low and slow,can be put down anywhere; AA5 not so.
The workload is high, forward planning essential, and it's much easier if there is another pilot helping with map reading/local knowledge. But it can be done, with less safety than cavok, but still safely.
One of the tricks to learning this is controlled and deliberate exposure to gradually worse and worse weather. Going from being a fair-skies aviator straight to tackling VFR at the minimums isguaranteed to shorten the life expectancy, regardless of total time aloft.
I don't have a lot of total time at all, but I know very well what my limits are likely to be on the day, on the type, for the route. And GPS doesn't feature at all in this process. GPS to me is a useful monitoring tool, that's all.