LA to Vancouver BC round trip

Hi, we are a family of 4 (2 teenagers) arriving in LA on 13th Dec from Australia. We have just on 5 weeks, We plan to drive to Vancouver leaving on the 13th, we need to be there for 20th and leaving around 29th. Some of the places we would like to visit are San Francisco, Portland and Seattle and Las Vegas and we will be ending the trip with 6 days in L.A. My questions are, Which would be the best order to do the trip, and which routes to drive, taking into account the weather, we have never driven in the snow , and dont want to do anything risky, we would like to see some real America and not just do touristy things, but I know we are coming at the wrong time of year and have to take into account road conditions.
Looking on Mapquest there is a direct route between Vegas and Vancouver,
I-90 I-82 and I-84. is this a good idea at this time of year?

First thing - if you are arriving at LAX on the 13th, I highly recommend you spend a night in the LA area to kick the jet lag before starting out on a road trip. This still gives you 6 days or so to get to Vancouver.

Of course, there is always the possibility of snowstorms in December and January in that area, but the mountain states do an excellent job of keeping the Interstate highways open. Worst case, you may have to find a hotel or motel for a day or two. If that route does not look good for whatever reason at that time, there are alternates to Vegas from Vancouver that are a lot less likely to be snowed in - such as I-5/CA-58/I-15. If it would make you feel more secure, you could rent a 4wd SUV for your trip.

As glc has already mentioned... spend a day or so in LA just to deal with the jetlag. Those 14+ hours in the air and the time difference take a bit of getting over.

Remember Peter Brock!

Lifey who prefers to wait for 36 hours

I think you should have the best luck not dealing with snow or ice if you take I-5. The main place where bad driving conditions might occur is the Siskiyous which is, basically, at the California/Oregon border.

But your other route might be fine, too. You'll really need to watch the weather forecasts.

4WD can be an advantage in deep snow but really doesn't give you much of an edge in ice. In fact, I see more 4WD vehicles spinning out than other types of vehicles. I believe this is because they have a false sense of security in their 4WD. Planning your trip so you can drive more slowly and safely in bad weather is more important, imho, than 4WD.