Funeral Pyre. Cremating my deceased 20 year old Geriatric Cat

my cat died of natural causes after 20 or so years. He has been my cat for 15 or those. Winter time in Iow means a frost later in the ground down to about 6 feet so digging a hole for burial is not practical. I didnt want to have to guard him from scavengers until the thaw so cremation is the only acceptable answer to me. Te Vet offered to throw him in a trash bag and discard with the trash. I declined the offer.