I have Lupus so stiff fingers can be a problem for me. I haven't seen the gloves you describe, but keeping your hands warm is the best thing. I use fingerless gloves (my son calls them Hobo Gloves!) they leave the ends of your fingers bare so you don't get into a muddle. I try and take regular breaks, and swap between handwork and machining. I have three projects on the go (2 machine and 1 handwork) so that helps.
It is frustrating but if you alternate and take the breaks, you get more done with less pain in the long run. Happy sewing!