If you are a unicum player and win 100% of the battles… You would need about 15.5 Avg Battles per Day if you play every day and complete your daily missions. This does NOT include the extra Battle Pass points you receive from completing the points you can receive for each tank (Tier 6 = 100 Points Limit receives 15 Extra Battle Pass Points).
Now below is a "ROUGH" estimate… But an above average player would probably have to play at least 20 battles per day + 3500 Gold to get the new Premium tank.
Note: 15.5 avg battles ONLY is a valid statement if you have a 100% Winrate.
Source: https://www.reddit.com/r/WorldofTanks/comments/102awbc/battle_pass_special_judgment_day_grind_grind/