Some random thoughts:

I think that TATL or TPAC travel with a toddler would be more comfortable with three seats in economy comfort, rather than two seats in business. This would be especially so if you can get bulkhead seats, which have more floor space where a child could play.

When my kids were little (long ago) there was a magical time around age 2 1/2 when, from one trip to the next, they understood what was going on with plane travel and accepted the fact that they could not get up and run around. YMMV according to your child's personality and experience with flying.

I lived for a year and a half in Norway when my kids were small. In general, I think the Scandinavian countries are wonderfully easy places to travel with kids, with benevolent attitudes towards children in public places such as restaurants and stores (you can bring a stroller everywhere), clean and safe environments, great public transportation, English spoken everywhere, and generally a low degree of hassle for travelers and parents. I would rate Denmark especially high in terms of attractions for kids that have some appeal to adults as well: Tivoli in Copenhagen, Legoland, beaches, ruined castles, and the island of Aeroskobing with towns that look like miniature toy villages. Another lovely Scandinavian destination, relatively unknown to Americans, that would be great place to hang out and explore for a couple of weeks is the Swedish island of Gotland (principal city: Visby) in the Baltic Sea. The obvious downsides to Scandinavia as a destination are colder weather and cost.

PM me if you find the idea of Scandinavia appealing and want more suggestions. Although we lived in Norway (Bergen and Oslo) we traveled quite a bit in Norway, Denmark, and Sweden, both by car and public transportation.