Retile

This is where math comes in handy….
Or do the logical thing and put down snap lock flooring.

Just determine how many tiles you'll need and weigh one. I've installed a lot of both ceramic and pocelain tile over the years and can't imagine installing it on a non monolithic surface. It's never a great idea to install those kinds of tile over wood floors in a house. An isolation barrier imo would at the minimum be necessary and a latex additive to a water based grout for flexibility if water based is what you're using.

I might just look at the number of square feet you will put down and then weigh the tile you are considering and weigh a piece. Just figure the weight it will take to cover the area and add a few pound for the glue and grout.
Like others have said, it is going to add considerable weight if you use ceramic tile.

We had carpet in the bedroom, bath and living areas with tile in the kitchen. Replaced it all with a wood look vinyl and it's much better. No more grout to clean between the tiles and much more comfortable under foot than tile.

Well would it be an issue, only way to really tell is to know what amount of weight would case an issue. Scales would tell you what your rig weights now, and then you figure how close you are to the gross allowable weight. If a couple of boxes of tile will put you at or over that number, then your stuck, NO. But it would be my guess would not make one bit of difference. They make a glue that the motorhome manufacturers are using so contacting them for what is best would be my suggestion.

I have like 6x6 tiles in the kitchen area. Carpet in the bedroom and living room.

What size tiles do you have now & have they cracked? I imagine the larger the tile it's more apt to crack. Yes, tiles are heavy, you could probably look at the box & figure it out. I would probably go with the vinyl.