This is because I've been the other way twice, once as far as the St John river in Canada. For me, upwest would be new and different.
I wouldn't let weather influence my choice - could be nasty either way. One thing I would definitely do is upgrade my ground tackle - swap out your spare anchor for something bigger and heavier. I normally cruise with two anchors and rodes - both 22# Danforth with 200' of 1/2" nylon rode. When going 'away', I leave one of those home and take a 40# Danforth with 250' of 5/8 rode.