Great thread - watching also with interest. Any comments on Grand Canyon visit for a married couple 60+ who are not into hiking, rafting, etc.? Like the train referenced earlier.
I prefer visiting the south rim off-season to avoid the crowds, and I absolutely love the views of red rock desert in the winter. Roads and view areas that are bus access only in-season are able to be driven in personal vehicles, hotel prices are way down and folks are generally more pleasant. Wildlife are more active, spotted a good few sheep along with plenty of deer and elk, very easy to break out the spotter and tripod at view areas and just glass around without a bunch of people getting in the way, right along with setting up the camera on the tripod and getting good shots of the wife and I rather than quick selfies from a phone camera or asking strangers to handle your $2k camera to take a poorly composed and out of focus picture of you. Yes, it will be cold and windy with snow chances too, coming from Wyoming the weather is pretty nice for us though. The train runs year round, a great way to take in the Village and drive the rest of the park another day.
Tusayan off the South Rim entrance is a great little place for nearby off park lodging, food and supplies. Williams is a decent drive away with freeway access for everything else. North Rim, you are in the middle of nowhere and it's awesome for that, but you are smack dab in the MIDDLE OF NOWHERE so plan accordingly.
Hiking in the winter is treacherous on the south rim, as many spots of the trails see zero sun for months and will have serious snow and ice in areas. Never tried it, but sounds like a fun adventure in my younger years. You can hike south rim to north, sure would be an experience. I'd have full on crampons though, that's for certain.
North rim, only open in fair weather seasons. Spring and fall are always best for avoiding the major crowds of summer vacationing families, and also avoiding the blistering heat.
Heed well the advice above about water, especially if you don't live and do a lot of outdoor activities in the desert or are not seriously acclimated to the brutal dryness and heat or cold. Plan for a
minimum of two gallons per person/per day along with supplements to replace lost salts and other vital nutrients, regardless of season and temperatures, and know all water points available.