Tbh, I'm generally a summer fisherman. I have avoided going when it gets below 6c at night. My bag is a big snooze+ 3 season jobby.
I'm over 50 now and am fed up with being uncomfortably cold without good bl**dy reason. So, a heated blanket for a few hours with the bed cover so I'm not climbing into a freezer seems like a sensible idea and a weight sacrifice I'm willing yo make. It runs off my Ridge Monkey Vault 26000mah powerbank which I take anyway, so its a negligible change for me.
I don't get the self flagellation at the altar of discomfort. If your doing something to save weight great you do you, but doing something just because it was done like that 30 years ago seems like madness to me.
20-30 years ago I smoked, mostly used a bike to get around and used to go raving. If I hadn't changed I'm not sure I would still be here, let alone have a decent job, house, be married with kids going to uni. If carp fishing had stayed the same we'd still be using argos sunbeds, optonics and cheap 50" brollies with a tarp over the top.
Just look at your phone in your hand. How old is that and how old is the tech?
The world changes, moves on and progresses. Embrace it where you want to/can justify it.
I would ask, do you use a throwing stick/spomb/bait boat/baiting pole/sonar/gps? None of those were available 30 years ago, at least not in their current form. Back then, were there any carp reels, rods with the specialised ringing we now use?