In that case, the cheaper (but not cheap) small and lighter unit the
inReach Mini might be of interest.
https://buy.garmin.com/en-GB/GB/p/592606Garmin are out of stock (at £300) but Amazon have them in stock for £275.
It has some limited routing functions but no maps, but it does give you weather updates (if you want), SOS, messaging, and track & share.
Battery life (1250mAh) is dependent on how frequently it pings location. If you set it to every half hour it'll last 24 days on a single charge. That drops to 4 days if you set it to every 10 minutes (the default). Of course you should turn it off at night to save battery, and you can take a battery bank with you to recharge in the field, there are some TINY ones out there.
A word to the wise though, I have (standard) Garmin and use and love it to bits, it's a
BRUTAL learning curve. You'll need to install
Garmin Express on a PC or Mac to update the Firmware, and the pair of you will need to get to grips with their
Mapshare software. And it's always wise to read the
online manuals as Garmin have a habit of updating them, so the ones in the box will be out of date (but still a good start) and reading everything in the
support centre will give you heads-up of potential issues, some of which might be resolved.