Water, mud and salt in the winter, are great enemies of a bicycle drivetrain, namely the crankset, the chain, the cassette and the derailleurs. In the video below, you will find a tutorial on how to prepare your bike for such an extreme conditions.
I think Scott Scale rocks in this segment! The Scale 920, with a cheaper version of their carbon frame, will feel much faster, than your very good indeed Merida.
Scott Scale 920 2020 https://www.scott-sports.com/us/en/product/scott-scale-920-bike?article=274591007
But in Europe, there is also the Scale 925 available: https://www.scott-sports.com/de/de/product/scott-scale-925-bike?article=274592007
Both are race ready and I would use them as a benchmark for other brands. The frame will weigh about 1200 grams.
There is also the Merida Big.Nine 4000, which is about 150 lighter, but I see it on the Polish website only. The German one starts with Big.Nine XT...