Not nearly enough information to provide useful advice.

Point balances in each credit-card program?

Mileage balances in any FFPs?

Starting city?

Ending city?

Maximum amount that can be charged each month between now and March?

My guess is that you can forget about getting five Business Class award seats to and from Europe in June -- especially if all five of you want to be on the same flights, and maybe even if you're willing to split up.
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