The range guess-o-meters are estimates based on the previous xx miles of driving. I don't know what the Clarity uses for this but I suspect 50 to 100 miles (more likely to be on the low end). The link app reports what the car tells it.
As you noticed, the EV range has gone up - part of this is warmer weather and part is the car learning your driving style.
The highway drive - how fast were you going? Speed makes a huge difference highway efficiency as the HP needed to push the car through the air goes up as the cube of the speed. Also, why did you have any charge left in the car when you got home? You should target zero EV miles when you get home to make the best use of both the electric and gas engines.
As for a break-in period - I believe there's a 500 to 1,000 mile break-in on the ICE where you don't want to run the ICE at a set speed for extended periods. The car's computer helps with this by running the ICE harder to charge the batteries and then drops back to run more on EV while keeping the overall power to the wheels consistent. Vehicle brakes also have a break-in period where you don't want to hard stop but you're beyond this. I know of no EV that has a battery or electric motor break-in.
2018 Honda Clarity Touring PHEV - Forest Green w/Tan interior (wife's car)
2017 Volt LT - Heather Gray; black bow ties, Charcoal VoltShelf
2012 Cruze ECO MT (hail totaled 5/8/17 103,600 miles @42.5 MPG)
2010 Mit Lancer GT MT (traded for ECO @31K miles)
2002 Pont Montana AWD - title to son at college graduation
1990 Pont Transport (traded for Montana @240K miles)
1986 Fiero GT MT (traded for Transport - needed more seats)
1985 Fiero 2M4 MT (traded for Fiero GT @8K miles)