The city, no matter when you visit it, is amazing and welcoming. During the morning you can take advantage of the beautiful panorama of Lake Argentino, with its unique blue to take pictures. And at night, despite the cold, it is great to have a beer and share experiences in the different excursions they offer.
A place to visit that I highly recommend (spoiler: not suitable for acrophobics) is the Cerro Comisión or Los Elefantes! Through a path that at first is signposted and then gets lost as you go up the hill, you can appreciate even more the lake, as well as be fascinated by the mountains surrounding the Perito Moreno Glacier.
I highly recommend visiting El Calafate, which is one of the most beautiful places in all of Patagonia. I would definitely go there again and I would never get bored!