Whistler in early/late March, or Tahoe?

Hi
planning another jaunt across the pond [from Scotland]. I did Colorado a
couple of years back, and this time I'm pretty set on Whistler with Tahoe
running a close second.

My concern about Whistler though is the weather/snow, as I've heard it can
get foggy and the snow gets heavy. When's the better chance of having good
weather/snow - early March or late March? If I want to ski mush in the fog
I can do plenty of that 80 miles up the road here in Scotland without flying
4000 miles. Is the risk of bad weather/snow in March enough for anyone to
think Tahoe's a better bet? Other attraction of Tahoe is I could do a
different area every day [I cover a lot of miles and get bored easily], not
sure how much variety/size there is at Whistler - sure its big for North
America but it's not "European-big". Current attraction of Whistler is the
transfer, as I'll be using up some air-miles and I can get flights to
Vancouver or SF, but not Reno, so Tahoe would be a drive from SF. (Can't
get a free flight to SLC either, to that was Utah out).

Anyone any idea of relative costs too? The Pound/US Dollar is great for us
Brits right now, and having been to the States many times over the last 20
years I know what my pound/dollar will buy. Never been to Canada though, so
interested in the relative costs of Whistler versus Tahoe.

Any any other comments gratefully received. I should maybe add that as this
is my annual break from the wife and kids so I go to ski [early to bed, hit
the slopes early] so relative merits of nightlife and non-skiing activities
has no real interest.

Thanks

Willie