Shawnalynn,

I would definitely wait for a stretch of good weather. You will probably want to make 2 stops for overnights. It can snow the entire route, not just mountain passes.

Haven't you taken your trailer anywhere in the west? Could you talk the buyer into coming to pick it up? An Ogden resident will be much more likely know how to drive in snow.

Personally, I would wait until summer to do this one.

The horrible bus crash yesterday (9 dead 26 injured) happened on I-84 13 miles east of Pendleton. This would be on your logical route. Deadman Pass is a place I would not want to be towing anything if the highway suddenly freezes.
Unless they are planning on taking it to Arizona for the winter, I would plan for a spring delivery.

Actually - the buyer lives in Denver, CO and suggested meeting in Ogden.

*sigh*

I was afraid the advise would be to wait until spring - good advise it is for sure.

Thanks!

If you decide it must be done in January or February, I would try taking US 26 past Mt. Hood to Madras and then south on US 97 to Bend and US 20 through the High Desert spending the night in Burns. Continue on US 20 through Ontario, OR to get on the safer part of I-84 in Idaho. Meet your buyer in Twin Falls.
Make sure you have enough tongue weight.

Talk to the buyer. He/She will have lots of mountain driving too, returning from Ogden pulling a trailer. Price Canyon and south to I 70 can be scary. I have been on I70 in Utah in a blizzard and that isn't fun either.