Can our RV be repossessed and leave us on the streets or can we claim it as our homestead filing chapter 7?

Claiming an exemption and holding onto a property that is collateral for a secured debt are two different things. If you owe $80K and the RV is worth $40K, you have no equity, so there is nothing to exempt. You cannot NOT pay the debt and KEEP the collateral. There may be a way to prevent the repossession through chapter 13 or perhaps the lender would be willing to modify the terms but you need to seek guidance from a bankruptcy attorney on this. Truly and honestly, this is too difficult to navigate this on your own. Your home is at stake here.

While a homestead exemption may cover your RV, you are not asking the right question. Exemptions are designed to protect any equity you may have in an asset, so that a bankruptcy trustee or judgment creditor may not take it to satisfy claims. Exemptions are meaningless with regard to a secured creditor's interest in the asset. You do not have any equity in the RV, so there is nothing to protect by use of an exemption, and the bankruptcy trustee would have no interest in it in any event, since the loan balance exceeds its value. Even if you did have equity in it, you cannot use an exemption to wipe out the secured creditor's lien rights. It could be worth $40,000 and you may only owe $10,000 on it, but if you stop making the payments, the creditor would still have the right to repossess it, regardless of whether you are living in it.