It really comes down to what your vehicle needs and expectations are. Used as intended, for commuting for most people, the i3 is more than adequate. If you intend to use it as an only vehicle, the REx is probably called for. Either of those configurations will have some limitations and inconveniences that you may or may not want to live with.
If you do need the longer range on a daily basis, a bigger battery pack can help, but one thing to consider is that with any larger battery pack, if you do exceed its range, it will take longer to refill from empty than an i3. Being able to maybe skip a charge point or two or more is an advantage, and from what I hear, the Bolt may be a better long distance vehicle...it does have more room in it at least for the number of people and storage.
Neither car is what I would consider an only car for the family where you could just get in, run the fuel nearly out and refill in 10-20 minutes and be back on your way. For that, you need a pure ICE or a hybrid with a larger gas tank.
So, given the depreciation on your existing vehicle, depending on your needs, a new car may or may not be a good financial investment, either. Given the age of your vehicle, you probably have another two years of free maintenance, but the things do not require much of any. Given that the Bolt is just literally a few days old in the buying public domain...it wouldn't surprise me that it will require some frequent trips for software updates..,the i3 is more mature in that aspect with going on 3-years of field experience in customers hands.
The allure of a new vehicle can be overwhelming. Not having seen a Bolt in person, I can't say what the interior will be like living with one or whether I'd even fit comfortably which is the first criteria I have when looking at a car...can I get In and out of it easily (I don't bend well, and I'm tall - long-waisted, too). My general finding is that few cars meet my coarse 'fit' test...the i3 barely does.
As to reliability...really hard to say both from a vehicle and dealer standpoint. On the i3, some dealers invested in the tools and training, some did not. My local dealer is one of few certified body repair points in the region, too, and have devoted a fair amount of money on training. It shows...plus, the service manager is fairly young and bright - open to the intricacies of an EV. I'd be surprised if that were true most places, though, and even less likely to happen at a Chevy dealership.