We are Canadian full timers. Generally speaking we spend winters somewhere south, be it the USA or Mexico, although next year we are headed back to Spain for part of the winter.
Canada has no laws on how long you can stay out of the country. It is a free country and you can come and go as you wish. However, your provinceial health care provider may have limits on how long you can be out of the province before they will suspend your health care priveldges. BC, Alberta, Ontario are 7 months, some are shorter some are longer. However most provinces will give you a waver on this every so often if you inform them by letter. Again, each province has its guidelines. As someone else mentioned, travel insurance policies for outside the country will need to know if they are the prime insurer or the secondary insurer. eg, if for some reason you are not covered under your provincial healthcare plan there rates will go up, depending on the Country you are visiting. If you are visiting the US expect them to be VERY HIGH. Not so much for europe or other destinations. Many Canadians leave the country for years at a time and simply get expat policies. Again it will depend on where you travel on how much it will cost. European policies will be a few hundred per month, American policies will be North of 1000. Depending on where you go you may just choose to get a repatriation type policy that will get you back home once you are stabilized. The actual medical care you receive at the other end will be on your dime. eg, you have a heat attack in spain and need a quadruple bypass and 19 days in the hospital, it will cost you about 11500 dollars or roughly what it costs in Canada. Some people will just make sure they have the money in an emergency fund and go from there. Heads up though, in the US this could cost north of 80,000 dollars so self insuring might not be the way to go there.
Take it on a year to year basis and insure accordingly. Don't overstay your max stay in the US though as both US immigration and the US IRS tend to get uppity about that kind of thing. If you feel the need to be south longer go into Mexico for a few months. Great country to explore.
As far as home address goes, many buy an RV property as their home address.
Good luck and have fun.