well you know it isn't that obvious always.
seriously devs could tell players about it on some point.
well i guess someone could make more graphic guide and pop in post 1 or dev in main menu, but thats pretty much with all games that got seasons
most common you got option to name your save and load it same as here
this version as is here got quite few games too , you scroll true the end and start/continue new game in next season, 1 example motherless
or you got button to click and load last save of previous season, 1 example timestamps
and thats all that is to majority of save continuations between seasons
ok there is also most annoying way too, no transfer but 20? (usualy without context too) and now you remember what you did year or more ago when you were at some points of game - example bright lord