When to send invites

I would send them by February people need time to book stuff off work, make flight arrangements, call around for hotel pricing etc. the earlier the better

The invites are ready electronically, then go for it since you know overseas family and friends have to make arrangements for visas and tickets. Getting responses back will also be good as early too to know that you can start your guest count towards the vendors and venue needed. The accommodation information will also be great for your guests to take care of their booking ahead of time too provided.

If you have already sent save the dates, you can probably get away with sending invites 3-4 months before the wedding.

I would say to send them out any time from the 6 month mark till the 3 month mark. I would normally say sooner rather than later since you picked a long weekend but if you sent out Save the Date's then that shouldn't be a problem.