Dear DuckMuck:

There are 2 main reasons to change the oil before leaving:

1) Your car is ALMOST due for an oil change (5000Kmiles).

2) Leaving the old oil in your car for 2 months (and it's cold where you are) will cause sludge and dirt to settle down at the bottom of the oil sump, possibly forming a hard crud (not good). So you would better off changing it before leaving.

Best regards,

Eric