I find Morrison’s Tesco Asda or other supermarket own brand chocolate eclairs are surprisingly quite low in carbs. It’s not the larger posh Belgian chocolate ones but the smaller cheap ones of 4 in a box. The lowest I’ve ever found is 7g per eclair.
I think it’s because Choux pastry is not that sweet, cream is ok, and just a small thin layer of chocolate on the top. I know a purest would say totally bad but I don’t drink alcohol and like you sometimes I want a treat and think it’s better than a donut or a lot of other things