TPMS and multiple sets of wheels

[WINNIPEGS_MOST_WANTED]

Here is my dilemma - I'm looking at getting some rims for the pathfinder. Here in Winnipeg they put tons of salt down when the roads get slippery, so I want to put some winter tires on my old rims and use those when winter rolls around. Then in the spring I want to switch back to my summer set. So questions for the people with aftermarket rims:

What's involved (TPMS wise) with going to an aftermarket setup?

On the '03 pathfinders is the TPMS direct or indirect?

Will I have to go back to the dealer to have the sensors reset every season or is this something I can do?

Any help would be appreciated.

[WINNIPEGS_MOST_WANTED]

*bump* (where's fueler when you need him?)