I am new in the field of time series data analysis. I am trying to forecast Production data by using SARIMA models. There is a clear seasonal pattern in the data. Unfortunately, I only have 41 observations in total that I can use to build the models. From theory, I know the test dataset should be at least 20-30%, but as my dataset is too small, I am doubting that if only 30-32 observations are enough to find the best models from a GRID SEARCH? As in this case we are not considering the most recent observations.
So, what should be the train:test ratio in my case?