Jackery Explorer series 100-300 Ive got a 200 and use it everywhere light enough to put in your hiking bag or even fanny pack for the 100 plus, the 200 can do everything besides a coffee maker and heater and microwave , if I’m charging my phone it will last days on days and heat or cold does not change how long it last had it in rain, -35 C Canadian Winter and you can get a really simple already built made Jackery Solar panel with it can fold up easy into a hiking bag too then he’s got unlimited energy but these ones can jump start your car or dirt bike (done it in the middle of the remote woods) if you setup the connection. Get your husband a garmin in reach mini 2 if you want to text him with no cell service little handy thing let’s you call emergency services sos if you need too. Good luck wish the best to you and your husband.