Hello everyone - we made the drive down over the last two weeks, just ahead of the bad weather. I want to thank everyone for their input. I made good use of all your advice and the route info. Very much appreciated!!
Here's a little update for those who might be searching for this information in the future or interested in hearing about our experience:
We had a couple of golden trip rules - no night driving and have your hotels booked in advance. Both proved to be good rules. We stuck to the US interstates but found they are full of big, fast trucks so it wasn't as leisurely a trip as I had envisioned. There are plenty of rest stops where you can get out and stretch, use the toilets etc.
We enjoyed our first night on the New Jersey shore and the view of NYC very much. Next stop was Richmond, Virginia - didn't get in until late and left early the next day so didn't do the place justice. We spent two days in Savannah - historic district is lovely. Next night in Pensacola FL right on the edge of the ocean and the town was literally empty of people and it was really quite chilly. But we wanted to say we saw the beach. Good pizza at Papa's Pizza. Two days in New Orleans (could have spent a week here!) and two days in San Antonio (River Walk was all lit up with Christmas lights - very nice). Really glad we took our time coming down and hope to do the same again on the way back home in the spring but may take secondary roads rather than the interstates just so we can see the countryside a bit more.
Attn Canadians: Definitely get medical insurance for the US part of the trip at least. My normally very healthy husband got some kind of food poisoning and we had to seek medical treatment at a walk-in clinic. We didn't actually use our medical insurance but I kept thinking...what if it had been something more serious!?$$$$$
We drove south from San Antonio for a few hours and crossed the border at the Laredo. I had spent a few sleepless nights going over and over which border crossing to use. Hubby was set on Laredo...so it was pointless to argue. Well, we had exactly zero issues and I felt silly for all the worrying I had done in advance. Maybe we were lucky or maybe you shouldn't believe all the horror stories on facebook? In fact the atmosphere was quite festive and the Mexican authorities were friendly and helpful. We had applied for our FMM tourist visa online from Canada. In hindsight, it probably didn't make a big difference in the amount of time the crossing took but the Mx authorities seemed pleased that we had tried the new website. I did have to return to their counter at one point to get my 180 days because they forgot to mark it down the first time. Not a big deal. Getting through the process for importing the car (TIP) took about 1 1/2 hours because of all the pre-Christmas travellers but went very smoothly. The process is well-communicated with signage and people were very patient with my poor Spanish and again there were lots of Mexicans willing to help me and chat about their own experiences. At no point did anyone ask to look in the car or seem even the least bit interested in what was in our suitcases although we had everything documented and numbered in case this were to happen. There was a security vehicle offering to accompany a convoy of travellers to city limits but we decided to skip the wait and head out on our own. No regrets.
Uneventful drive from border to Monterrey on the cuota and then through to Saltillo where we spent 1 night at Sheraton Four Points just north of city limits - this is a simple hotel but we felt safe and there was a surprisingly good onsite Mexican-Lebanese (!) restaurant. We somehow missed the cuota coming out of Saltillo where we got onto a libre by mistake but made our way to Aguacalientes without any problems - we pretty much had the road to ourselves at one point. Although I did think that if we had had car problems, we were in the middle of nowhere...so I second the advice to stay on the cuotas ...which can be a bit hair-raising at times when there is no divided highway but at least there are places to stop and gas up or ask for help.
The navigation app on the car was invaluable to making this a less stressful trip. We made use of cellphone apps quite often and I was grateful for MakeItSo's advice on being able to roam (Roger's "roam like home" at $15 Cdn/day). We also brought our garmin and made sure it was loaded with the Mexican maps but as it turns out we didn't need it. Also, I bought a "televia" transponder at the Oxxo in Nuevo Laredo so that we didn't have to rummage for pesos at the tollbooths - we just drove through without stopping. It cost $150 P and you can load them up to $2000 P. There was one toll booth where the system wasn't working but not a big deal if you have cash - so do bring some pesos with you. And just a note - credit cards are not always welcome.
We took the Guadalajara by-pass to Chapala and thought we were very clever only to screw up and miss getting off at the right exit - it does not say Chapala at this point - it says back to Guadalajara. So we ended up on the cuota to Colima by mistake.🙄 We continued along for about 40 km cursing ourselves and then lucked out and saw a tiny sign for Chapala which got us onto the back roads north and west of Lago Chapala. It was slow going to make our way back and lots of topes but kind of a nice end to a long trip as we started to recognize things and feel like we were "home"... We arrived at the top of the libremente just as the sun was setting over the lake.☺️
Thank you again to all who answered my request for information. We'll be heading back to Canada in April if you have any other suggestions or recommendations!
Happy New Year !