I'm not sure if I would use invisable thread, the shine might be a distraction. Pick a few varigated thread that blend with the colors.
As for the batting ..Hobbs 80/20 does have a bit more loft than Warm and Natural. Or use the warm and natural and use spray basting and cut some lower loft poly in shapes and add on top of the Warm and Natural ,where you want more loft for quilting definition. It easier to add the loft areas by spray basting the batting , or top on the wrong side and trim . That way you can see the areas on the fabric back.
Your quilt is beautiful.