gearoot Rechargeable Heated Insoles with Remote Controller, 4 Heating Levels, Wireless Foot Warmer, Winter Thermal Insoles for Outdoor Hunting Skiing Fishing Hiking Camping Men & Women https://www.amazon.com/dp/B08DSVR218/ref=cm_sw_r_apan_glt_fabc_H9GKHAWXSF6C6BYDX9WG?_encoding=UTF8&psc=1
Plus heavy wool socks.
Good base layer and electric heated shoe insoles.
I use these
gearoot Rechargeable Heated Insoles with Remote Controller, 4 Heating Levels, Wireless Foot Warmer, Winter Thermal Insoles for Outdoor Hunting Skiing Fishing Hiking Camping Men & Women https://www.amazon.com/dp/B08DSVR218/ref=cm_sw_r_apan_glt_fabc_65NVTG6WHCBH06C2BETF?_encoding=UTF8&psc=1