With the solar lights, you get what you pay for.   I had tried heap solar lights and the panels only held up for a season, as noted by Amos. The ones I have now are still working well after about 5 years. I don't notice a problem with them lasting all night in winter - but they are located where they are never shaded (full sun all day long) and we rarely have successive days of dark, gloomy weather.

Of course, we have also had a run of exceptionally dry winters and in the midst of the worst drought on record here.