What do I need to haul my 2108 DS Micro Minnie

Hi All, have a 2019, 2108 DS. At present pulling RV with a V6 Toyota Highlander with 5,000 lb towing capacity. It does alright on highway and small hills but larger inclines are a real chore for it. Sounds like I need something with more HP/torque for increased towing capacity. But how much is enough for long distance travel and frequent mountain climbs?? ... any thoughts and/or experience with this would be much appreciated... Thanks, Paul

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