Hot spring opportunities (Thanks for reminding me, Joe F.)
Minnesota had a lot of shallow swamps. They gave off heat at the end of the day longer than bare ground would.
Switching to thermaling over these swamps near the end of daylight would have me coming out of the air a half hour before sunset.
How about over a power plant water cooling pond
For years Minnesota Power and Light Co. kept Colby Lake from freezing over all winter long even through minus 30 degrees (F).
Sea Gulls would thermal up over the lake to glide 50 miles to Lake Superior which also seldom froze over during the winter.
Many days during the winter with snow covered ground surrounding Lake Superior the Radio data buoys would indicate the wind moving toward the lake from all directions. Sea Gulls could be seen soaring all day without flapping.