As you have read...you are limited in how long you can be away from Canada if you wish to maintain certain criteria.
Another thing to be aware of is...a non-US resident cannot take up a workcamping position in the US. Lots of CDN's think they can..and or used to do this, but not anymore. To set everyone's mind to rest, the same applies to Non-Canadian residents in Canada. It is a tax issue, even if money doesn't change hands, but instead is a trade? as in...campsite for X number of hours.
I hope readers note the post from John and Angela, about returning to Spain. We kind of fixate on travel to the US, and much of the concerns we have, as Canadians, is health insurance. As I understand it, health costs in Spain are pretty much in line with our own and if you had a health 'event' while IN Spain, you would pay and then claim it on your own provincial health plan.
Perhaps John and Angela will post that info?
Gary Haupt