Can't quite decide on route..WA to TX times two!

We are moving to the Dallas area next week from Seattle. The first trip will be with my husband driving the moving van, towing a pickup, and me driving the minivan with a utility trailer. Both of us are decent at winter driving but pulling our loads might make it awkward.
We did this drive about 5 years ago, going straight thru, alternating drivers, via Boise and SLC and OK. (40 hours with bathroom and food breaks) On that trip (March weather) the roads were OK but my son got nosebleeds from the elevation. I think he's grown out of that but who knows. On that return trip (changed itenerary for nosebleeds) we went straight north to SD then cut over on I-90. Boring scenery but OK, and Rushmore was fogged in. &*(
This trip down, we have 5 days, and would like to possibly see the Grand Canyon. Is 89 OK in winter if we go Sea to Boise to Provo then down? Or should we stick to I-5/I-10 and avoid mountains altogether. Again, it's the trailers and the unknown UHaul tires that worry me. Any other "must-see" places with 5 kids ages 4 to 15?
SECOND trip is just me, returning for a few last days of work and my car, a sedan (again Seattle to Dallas). I am stopping in Vegas for 2 nights that trip (lucky me!) What would the fastest route down be? I can carry chains but do not have snow tires on. I want to go fast on this leg, I only have 2 days, maybe 3 to get to Vegas to meet a friend, then I can be as pokey as I want from LV to DFW. PS I commute 2 hours to work so I know my limits re:sleepy driving. I can do 10 hours easy at night.
Thanks for any opinions!

Welcome!

You are going to have to plan your route "on the fly" depending on specific weather and road conditions. On the way down with the convoy you are running, I don't think you will have time for any sightseeing, because you are looking at a 2100+ mile drive. This is 4 days at best, and you will need that 5th day if you have to detour around some bad roads or get slowed down by adverse conditions. I would look at using only Interstate highways. However, if the weather is favorable, the fastest route is I-90/I-82/I-84/I-80/I-25 to Raton NM, then US-64/US-87 to Amarillo, then US-287 to DFW. The highest elevation you will encounter is somewhere around 7000 feet in WY on I-80. If you have to go south first due to weather, then you are looking at closer to 2500 miles which is 5 days - period. I would not try to drive a U-Haul more than about 500 miles a day. Sorry, but I don't think the Grand Canyon would be advisable on this trip - that would be something better for you to do in warmer weather. It would be an easy 2 day drive each way from DFW and would be a nice 1 week summer vacation.

The fastest way, again, weather permitting, from SEA to LV is via SLC. 1250 miles, 2 long days. If you need to, the best alternate is I-5 to Bakersfield, then CA-58 and I-15. That's 1325 miles and can also be done in 2 very long days. Plan on having that 3rd day just in case.

Thanks Much! Do you have any web sites you recommend for road conditions? I use the WA DOT one for local stuff, are the individual states' sites the best way to go or are there Interstate sites for road conditions?
We'll make the Grand Canyon next summer's trip:)

Hello and welcome to the RTA forums !

Check out the federal site link in this thread for State road conditions.

Good decision regarding the Grand canyon, towing a trailer with a truck and having to take breaks etc with 5 kids while driving in convoy is going to be very work like, and will require 5 days minimum to arrive with your sanity in tact ! ;-)

I wonder if it was the elevation that caused your son's nose bleed, being in a moving vehicle for 40 hours without any proper rest would raise my blood pressure, and is certainly way beyond what we would recommend doing to stay safe and alert, and to be honest would regard it as reckless. Pleased you got away with it on this occasion, but wouldn't recommend you try anything like it again.

Have a safe journey.