The most common LTE bands used by Telus are Band 4 (1700/2100MHz) and Band 2 (1900MHz). Band 2 is one of the newer ones and has been deployed in the Windsor area and the iPhone should work with it. Both Band 4 and 2 appear to be widely deployed in the Windsor area.
700MHz is still being deployed from info I can find and out east there are only a handful of towers in Ottawa, Montreal and Quebec City that offer it. Most of the few 700MHz towers in the region appear to be in Quebec. Bell doesn't appear to offer 700MHz near Windor either. They have far fewer towers than Telus does in the area. Come out to western Canada if you want 700MHz right away. Plenty of towers here offer it. 🙂
If you're having reception issues near Amherstburg, the best thing you can do is use Telus's app to report problems with signal reception.