rear main seal leak questions??

[Awyman18]

ok so my 1990 supra turbo has a rear main seal leak. Its not awful...like a couple drips usually...also my 1992 toyota camry leaked from the rear main seal, but only during the winter time like my supra. Is this a toyota thing or just old seal thing? lol also, in the summer ur seals swell and such, and in the winter they shrink, think its only a winter thing considering its effing cold here? And last question is could a bad pcv valve be the issue? Or bad pcv= exess pressure + cold weather (seal shrinkage) = minor oil leak? Not a big deal if i have to change the seal, but if its something minor id rather do that instead of dropping the tranny and such