https://www.ebay.com/i/271762731742?chn=ps&dispctrl=1 Put these over your heated grips. NICE! Not Hippo Hands, but a LOT cheaper.
Some of my winter rides used to be remote, so I was warned not to rely on heated gear for remote rides. A failure on a cold remote ride kills folks every winter. I have cheap Chinese heaters on a couple bikes, but they are covered with Hippo Hands. Together, most any waterproof gloves will do. Lots more comfy than heavy, bulky, expensive insulated gloves.
Chemical warmers make a good back up. Different warmers make different heat, the hotter ones expire faster, the smaller ones expire faster, but some moderate heaters can last for 10-12 hours. Very nice when matched to conditions. Too hot can be insulated between clothing layers or vented, too cold is still better than no heat at all.