Invitation suite dilemma

So I knew from the start I would design my own stationery and paper goods for our wedding. I've done it for years for all kinds of parties I've had. During the STD designs I found Canva and man it is amazing! It has great formats and pricing and I knew I would use it for everything moving forward. I've been playing around for awhile regarding my invitations suite and I landed on a format I love. The RSVPs will be 5.5inx4.25in, the Detail cards will be 5.5inx5.5in, and the invitations will be 8.5inx5.5in. It all looks great together! But I learned too late that Canva won't print the 8.5x5.5 size, I'd have to print it myself. So now I am stuck with the situation of everything not matching perfectly or having to resize it all. I don't know what to do! I really like how it looks all laid out with the sizes I finally chose.