Replacing Battery in '03 Boxster

[986sport]

I had to jump start my Boxster the other day on a real cold morning (25 F)after not driving it about a week. Restarted yesterday morning OK, so battery is probably up to full charge again after driving it.

The question is whether I should just go ahead and replace the battery after 3.5 years and 37K miles. I don't drive much--maybe 5-6K miles a year. Clearly, I can't leave the car unused for a week in the winter without attaching a trickle charger.
It wasn't a problem in the summer.

Porsche offers the same battery for $200 plus install. Not maintenence-free!
Autozone has a maintenance-free replacement for $97. ($85 with the old battery)
It's a Duralast 48DL, 700 CCA.

I'm thinking of getting the Duralast and asking my Porsche dealer to install it--since I don't want to bother resetting all the electronics myself.

Does it make sense to replace the battery at this point? I have a trickle charger,
which might suffice for the winter. I just bought a jump starter so I don't get stuck anywhere.

Is resetting the electronics a hassle? I know you need the radio code (it's somewhere in my papers.) What about the on-board computer and windows, etc?
Seems like a job for the dealer.

This is a Porsche-certified car, bought used 8 months ago and still under 2 year warranty. I doubt I can get them to replace the battery ( the warranty says
batteries not replaceable if not maintained properly--whatever that means.)