About to enter Victory Road and then the Pokemon League of Platinum, how should I change my team up?

Aka, who can support Garchomp the best lol

I could really use something that resists Ice. As well as some bulky Pokemon that I can switch to tank hits.

I think it is time to get rid of Betty lol. Gloria has been my goat since day one. I find she has pretty decent defensive stats. I never would have thought I could have liked the Piplup line.

I know they have a lot of dangerous trainers in Victory Road.

Also, this is a QoL rom hack, so it has some differences from regular Platinum.