Training this winter

Asking on the Internet is gonna get you a whole load of shit information, mainly from people with no qualification with which to base their answers.

FTFY

70kg squat is a bit flimsy - if you really want to strenghten your legs you should be startting your winter weight training about 90-100kg and aiming to imrove in 5 kg increments till you 'top out' in March. A good improvement would 100 to 135/140kg.

Deadlifting is also very good but watch your back!

^^this