I don't own an InReach product, but according to Garmin all of the InReach products will allow you to load maps. The subscription is for the emergency SOS, texting and sharing location features, not the GPS/Maps functionality.
Something you might look into if you haven't already purchased an InReach......We use the Garmin Rino units for our game hunts and all of our outdoor adventures. GPS with topo/city maps can be loaded easily. The ability to communicate and pinpoint each others locations via the 5w GMRS radios with GPS and no subscription is almost priceless. I prefer the older units (530Hcx) but the newer units work just as great. They aren't cheap either, but all 10+ in my hunt group couldn't get by without them. If anyone new joins our group it's basically the first piece of gear we tell them to get. We use them alot on a daily basis sometimes talking with other hunters 25-50 miles away from us.
Sadly, cell service is creeping closer and closer to every square inch of our hunt areas. With such a big group, One of us always has a decent cell signal, with high elevations, multiple carriers, etc. it helps out in case of emergencies.
If you have a smaller group or go out alone I could see getting the Explorer. In my case having "invested" in a Garmin Rino well over 10 years ago an InReach Mini would be sufficient to supplement my Rino.
BTW the prices might seem insane on these units, but if its a tool you use regularly over the next 5-10 years and it provides peace of mind it's worth it.