We currently have 11 champions. Excluding special champs, that gives us 2 of each element type other than nature.
The new cap gives us 41 total heroes and 15 quests.
My heroes all hover in the 190+ range for elements using current tier and some affinity.
Using a combination of 1 champion and 1 hero, a 280 barrier is easily broken for 11 quests of the 15 slots and gives us 30 heroes to send out.
If we're doing quests of 4, then 22 are taken as filler for the first 11 and 8 are available elsewhere.
Those 8 would be sent without heroes and would only need 2 each for barriers. And with 4 quest slots that works out well, even if they're short on the number of heroes.
Even if/when we get 4 more champions we'd have 4 quests of only 2 accompanying heroes instead of 3.
So make it 45 max heroes and the problem is solved