Welcome Party

You cannot throw a welcome party and not pay for it. You can't invite people on your wedding website or directly and call it 'unofficial' either. But you can casually mention that you'll be hanging out at the hotel bar if anyone wants to say hello, but it has to be incredibly casually. By word of mouth alone, having your family and wedding party mention it to anyone they talk to who is also invited.

If you can't afford it (and be able to pay for EVERYONE at your wedding to come since you'll be putting it on your website) then unfortunately you can't have it. You can mention you'll be at the bar or whatever, but don't put it on the website. Then it'll look like an actual planned wedding activity and you'd have to pay

@A.Magill has it right. If you want to invite people to meet you at a bar and you can mingle, do it super casually and in a non-obligatory manner. My friends did this the fight before their wedding and it was a lot of fun, but most people skipped out and it was fine. We all paid for our own drinks, as well as the bride and groom though they didn't expect it.

Our wedding planner was allllll over us about doing a brunch the morning after the wedding. She even picked out a place and everything and the total cost was $3000 plus tip and tax. That was something we just couldn't afford, especially not for everyone. We have started casually mentioning to friends and family member we'll be hanging out at one of the bars on a street a quarter mile from the wedding location the Sunday after. We are not putting it on the wedding website or in writing anywhere. If people would like to come hang out, they are more than welcome to. If not, fine with us

Nope. If you're having a welcome party as a wedding event, you need to host it.

Welcome parties and morning after brunches aren't necessary. Skip it or pay for it.

Instead of a party how about little gift bags in people's hotel rooms? My mom put together a welcome/hangover kit that she saw on Pinterest.